Slavery has existed throughout history in different parts of the world and in different civilizations. Its exact definition is a matter of debate, as is the question of whether the entire range of historical and contemporary phenomena known as slavery can be narrowed down to a single definition. What is accepted, however, is the fact that through-out history civilizations have institutionalized the possession and ownership of human beings within juridical, social, economic and cultural frameworks.
The evolution of slavery in the Mediterranean was subject to the historical processes that this region underwent, which differentiated it from non-Mediterranean slaveries. different types and definitions of slavery, like other historical and human phenomena, should be distinguished and studied in the light of the social mechanisms within which they operate.
Studies have developed micro-historical approaches which revealed the unique characters and different forms of slavery that have existed throughout history, linking them all the same to the broader question about connectivity between different forms of slavery. This approach, which combines micro-historical study with a macro-historical conceptualization, is particularly useful for the study of the history of slavery in the Mediterranean, since it underlines the differences within one common geopolitical framework.
Mediterranean societies did not share one single definition of slavery, nor did theyconform to a single model. The uniqueness of Mediterranean slaveries lies in their adaptability to the geopolitical, cultural and social changes of Mediterranean reality, which forms their dynamic character. Mediterranean slaveries cannot be fully explained if we look for a single definition to comprise them all. What we need to look for is the ways in which different forms of slaveries emerged in the Mediterranean and the conditions under which they developed. Nevertheless, we also need to bear in mind that such conditions were not necessarily confined to the Mediterranean environment, but were also determined by links to non-Mediterranean civilizations.
Sources of slavery
Out of the four main sources of slaves, two concern people who become slaves in their own society: slaves by birth, and freeborn people reduced to slavery through legal or illegal processes. This could be debt-slavery, penal-slavery, child exposure, self-selling, or illegal kidnapping. In all these cases, the slave is part of the society in which he is born and in which he is enslaved. In contrast, enslavement of captives and prisoners of war and the trade in human beings depend both on geopolitical and economic aspects which relate the society in question to societies with which it is in contact. And from the point of view of the enslaved persons, their enslavement marks a change of environment and/or society.
When approaching the subject of Mediterranean slaveries, it is important to distinguish between the two types. It is the enslaved foreigners who reflect geopolitical, economic and cultural cross-Mediterranean dynamics. We will also find in this type the ways in which slavery in the Mediterranean is connected to non-Mediterranean regions. In this respect, human merchandise, whether imported, exported, kidnapped, or captured in military or private actions, is defined by a change in status of the enslaved person, and causes a forced demographic movement. Human trafficking, be it by war, piracy, kidnapping, debt-slavery, child exposure or self-selling, forced a significant circulation of human beings, against their will, in the Mediterranean world.
On the other hand, slavery was an integral part of different social structures in Mediterranean societies. It had functions beyond the economic, and must also be explained as an element which had an impact on the social, political and cultural aspects of Mediterranean life. This is what we can describe as the function of slavery in the historical evolution of Mediterranean civilizations. Slavery could not have played this role without having a versatile and adaptable character. This enabled the development of several methods aimed at possessing and exploiting human beings.
A Greco–Roman Mediterranean
During the second half of the first millennium bce, political definitions established a separation between the enslavement of local inhabitants, whose political status should ensure their juridical status, and enslaved foreigners. The definition of slavery is therefore related to the process of social politicization of Mediterranean societies. Imported slaves merely formed a segment of the foreign population in ancient Greece. Democratic or republican, Greek and Roman societies were not “free societies” in modern terms, and slaves were part of the majority who did not hold political rights.
In the third century bce, slavery became a common phenomenon, mainly thanks to common political, social and cultural structures. The right to subdue, own and use foreigners was institutionalized in Greek, Hellenistic and Roman societies, and differentiated slaves from other figures of social dependency by defining them as res, “a thing” to own, being themselves unable to own.
The special human character of this type of res was nevertheless acknowledged. And an elaborate system of thought supported by literature, religion and art produced moral and philosophical justification for the enslavement of human beings. The capacity of ownership thus became a demarcation between slaves and free persons in Greek and Roman societies. Roman law excluded the former in defining the latter as having a juridical personality, but did not make two classes out of them. First, slaves were not dependent on the free persons in society, but were solely subordinated to their owners. Second, although used more than free persons as a disposable labor force in mines and public construction enterprises, slaves did not share a single socio-economic status. This was dependent on their owner’s status and the position they held in his household. Moreover, a clear-cut division between slave labor and free labor, while desirable, is impossible to establish. In fact, it is precisely the absence of a single economic definition which reveals the function of slavery in Mediterranean societies throughout the history of the region. This becomes clear when the Mediterranean became Roman.
The Roman imperial period presents a unique phase in the history of the Mediterranean. It is the only period when the entire region was under a single government. In regards to slavery, it is also one of the more documented periods. Historiography, literature, law and archaeology of the many centuries of the Roman Empire reveal the functions of slavery, and the ways in which it was molded as an institution. In both republican and imperial Rome, the borderline between being a slave and a free person was dynamic in both directions. This meant that enslavement of free persons was practiced by the state on both war captives and inhabitants of the Empire who did not comply with Roman politics. Convicted criminals, dissidents, captives, or imported slaves: all shared the same juridical status. The Roman conquests, which were a long historical process, and the constant suppression of political revolts, ensured a continual supply of slaves within the Empire.
The concept of “penal slavery” made captives and criminals who were sentenced to death utilizable by the state in public enterprises, mines and games, but did not give them an exclusive economic role. In the private sector, slaves were particularly useful to set up economic enterprises precisely because of their unique juridical status, which made them dependable economically and socially, unlike employees of free status.
Through particular juridical institutions such as the peculium or praepositio, a master could establish a slave within the family business in both rural and urban milieus as a profitable agent, while also exploiting his economic activity for his own benefit. This made (male) slaves socio-economically unique, comparable, if anything, to unemancipated adult sons. It also made the economic expansion of the family unit dependent on the incorporation of slaves as managers. Manumission acted as a means of institutionalizing this social dependency to the benefit of both slave and master. The manumitted male slave, just like an emancipated son, inherited his master’s name, family linage and political position, and could well build a career for himself as an entrepreneur. This did not imply that slaves were treated as beloved children, far from it. Roman society defined the master–slave relationship in a framework of total dependency, a product of the potestas of the paterfamilias, the unlimited power of the father over the lives of his family members. The slaves’ loyalty to their masters was taken for granted, and although not acceptable for testimony in court (slaves having no juridical personality) torturing of them was a regular procedure.
Although not “slave-owning societies” in modern terms, it is impossible to think about Greek and Roman societies without the place they attributed to slavery. Slavery appears not only as part of the social structure, but a vital element in the evolution of both society and economy in Mediterranean antiquity. This was not due to the exclusion or the unique exploitation of slaves, but mainly due to their functionality. Slaves made society and economy dynamic thanks to their complex status: juridically they were like any other property, yet socially they were the opposite of any other type of property. The same social and economic importance of slavery as a dynamic institution continued into the medieval period, although its juridical definition radically changed.
The rise of a medieval Mediterranean
After the seventh century the Mediterranean entered a new phase in its history, with its division into three distinct civilizations: the caliphate, Byzantium and the Latin West, each with its own language, culture and religious identity. Slavery continued to play an important role in the socio-economic life of both Byzantium and the caliphate in contrast to its role in the Latin west. This difference marks the demographic and economic differences in the early and central Middle Ages between the rich populated southern and eastern Mediterranean regions, in contrast to the regions northwest of the basin. This economic imbalance created a new international dynamic around the commerce in slaves.
Another decisive factor was the role religion played as a political and national identifier. The new political definition of the state as religious community in both the caliphate and Byzantium affected the definition of the borderline between slave and free person. Medieval laws defined the free status of members of their respective religious communities as a permanent “civil status.” This meant that a free Muslim, for example, could not lose his status as a free person within the Caliphate de jure. However, he could well become a slave de facto in Byzantium, and vice versa. The religious identification that maintained the free status of the member of a religious community left the enslavement of foreigners as the only source of slaves. Legal measures were taken in both Byzantine and Muslim law to eliminate the enslavement of adult and child inhabitants either by legal punishment, self-selling or child exposure. Both states developed a new international custom: the ransom of captives and prisoners of war from the infidel enemy. Jewish communities shared the same perspective, and developed their own mechanisms for ransoming their co-religionists. Furthermore, prohibitions on selling co-religionists to slave traders and international conventions on redeeming co-religionists were aimed at limiting commercial trafficking in local inhabitants. These measures did not prevent piracy, by both private and public forces, which became a permanent threat in the central medieval period, and was aimed at filling the demand for slaves on the Byzantine and Arab markets. For the Mediterranean inhabitants who were victims of such activities that meant that they were de jure free persons in their homeland, while de facto slaves elsewhere.
In contrast to the clear-cut juridical demarcation between slave and free person in Byzantium and the Caliphate, the laws and juridical records of the Latin West suggest an amalgam of statuses of social dependency of peasants which also included slaves. The ambiguous meaning that the Latin terms servus, servitium, servitus (originally “slave” and “slavery” in Roman Latin) acquired in the Middle Ages corresponded with the fact that these statuses became mixed through marriage, and reflected the absence of a borderline between free and unfree. Slavery in the early medieval West seems to have been dependent on hereditary status, rather than on the importation of slaves. Nevertheless, western Europe played an essential role in the Mediterranean slave trade by connecting the southern Mediterranean markets to eastern and central Europe.
A lack of economic means in the regions outside of Mediterranean influence (central and eastern Europe, the Latin West) and the demand for gold in these regions created a new market economy. This supplied slaves from pagan populations in Africa and eastern Europe to the southern and the eastern Mediterranean basin as well as to rich Abbasid Iraq, where the demand for slaves was high, and the financial means of acquiring them was available. The trade routes of African slaves ran from the sub-Sahara and east Africa to the Mediterranean south (trans-Saharan routes) and Near East (via the Persian Gulf), and of European slaves from northeasternEurope to the Byzantine–Arab Mediterranean. The latter were called (in the Arabic of Andalusia) saqaliba, referring to their Slavic origin. The term later entered Greek (sklaboi), and all other western European languages. This economic dynamic reflects the new function of the Mediterranean as a place of encounters, exchange, war, commerce and human exploitation between medieval civilizations which were not Mediterraneano-centric, but evolved through international relations outside of the Mediterranean.
The religious aspects of both medieval law and social life affected the status of the slave, in particular in regard to the slave’s family life. Whether originally of pagan origin, trafficked and sold in the Mediterranean, or a Mediterranean inhabitant who was kidnapped and sold in a foreign land, the slave was expected to follow the religion of the owner (hence the importance put on ransoming captives from the infidels).This in no way resulted in immediate manumission. Nevertheless household slaves were likely to be manumitted before their owner’s death, but remained in the service of the family.
While under Roman law no marriage could exist between a free person and a slave(though concubinage was customary), the development of marriage as a Christian institution brought about a juridical acknowledgement of the marriage of slaves within the framework of the Church, and juridical restrictions on splitting up families by selling or manumitting their members. An equivalent process is apparent in Muslimlaw, which forbade the separation of mother and child through sale. It also gave a unique alienable status to the slave mother of her master’s son. Questions of themixed statuses of married couples were discussed in Christian, Jewish and Muslim jurisprudence alike. The basis for them all was the emphasis in religious literature on the humanity of the slave, thanks to his or her identity as a believer.
This movement in the juridical status of the slave from a thing to a person in distinct medieval legal systems was paralleled by the gradual intervention of medieval public authorities in the private powers of the owner. In a word, although owned by their proprietors, slaves were also under the authority of the sovereign. Incarnating the law the sovereign controlled all juridical definitions of social statuses. One example of this is the juridical assertion in Byzantium, according to which a master could not unite his slaves other than by Christian marriage, and the parallel in the Latin west, where Christian slaves did not need their master’s approval to be married in Church.
Whether slaves continued to be used in agriculture is a matter of debate, and depends on the interpretation of the medieval evidence. Well-documented thanks to the historian al-Tabari, it is a unique case of substantial evidence surviving on the role that African slaves played in Abbasid agriculture. The evidence from Byzantium and the Latin West for the early period, although scanty, points clearly to the rural use of slaves in these regions, always alongside farmers of free status: dependent tenants, landowners, or hired workers.
In urban manufacture the use of slaves as agents and guild members raised the socio-economic position of the household. As in antiquity, slaves were also acquired by rich medieval households as domestics, but unlike Greek and Roman societies, both Byzantine and Arab societies used slaves in militia forces and as bodyguards. The fact that Sunni law gave sons the status of their fathers made it particularly useful for a male slave owner to enlarge his household through the sons of his female slaves. Polygamy and multi-concubine female slaves, both customary in Muslim societies, proved more advantageous for the expansion of the household in comparison to Christian or Jewish societies. In contrast, in Byzantium the child of a slave mother, male or female, was a slave and was named “born in the house.” But the term “my men,” which was a mark of social status, comprised all male persons under the influence of a single master. Women, whether slaves, manumitted slaves, or concubines, were merely the vector that enabled hierarchical male kin groups to form. Manumission perpetuated the social dependency of both slaves and their descendants within the family, while integrating them into the socio-economic structure of the household at all social levels.
The most characteristic example of the versatile nature of medieval slavery is to be found in the military function of slaves in the Arab world. The Mamluks, literally the “owned,” were imported as boys from the Eurasian steppe and the Caucasus to form the military elite of the Muslim political leaders. They were trained in special military schools, converted to Islam, and manumitted. They could marry, but could not pass on their position to their sons. The entire institution was based on the perpetual importation of enslaved boys, often of Turkish origin, detached from their family and country, in order to generate the continuation of this elite military institution.
The Mediterranean slave trade changed in the late medieval period in view of the loss of the commercial hegemony of Byzantium in favor of the Italian cities. Amalfi, Bari and Venice connected the central and eastern European trade routes to the south-eastern Mediterranean markets already in the central medieval period. In the late medieval period, the Venetian and Genoese commercial monopoly in the eastern Mediterranean and the Black Sea embraced the importation of slaves of Mongol, Tartar, Turkish, Caucasian, Greek, Russian, and Balkan origins. The treaties that Venice signed in the fourteenth century with the Turkish emirates resulted in the importation of Greek slaves from Anatolia via Crete to Egypt and Italy.
The new economic position of the Italian cities was followed by an increasing demand for slaves. These were used as domestics, as workers in small urban enterprises and as oarsmen in galleys, but by no means exclusively. The large numbers of imported slaves per boat (from a few dozen to a few hundred), reveal the increasing use of slaves in southwestern Europe, in comparison to their disappearance from northwestern Europe. The disappearance of both slaves and serfs in late medieval western Europe has been explained against the background of the rise of an ordo laboratorum, a new order of workers, that is, free peasants working in the countryside and paying a tithe for the land they cultivated. This formed the back-bone of the economic expansion of western Europe, and restricted the employment of slaves in western European economies in contrast to Mediterranean Europe.
The expansion of Aragon in the late medieval Mediterranean led to Aragonese merchants playing an important role in international trade. They supplied slaves to western Mediterranean markets using the slave market in Mallorca. In Italy a new system of physiognomy was developed, which aimed at revealing character attributes according to the slave’s physique and in particular the pupil of the eye. This was another phase in a long history of racism aimed at finding ways of determining the nature and the behavior of slaves, as well as justifying their exploitation.
As in medieval Byzantine and Muslim societies, the backbone of Ottoman social life was the private household. Placing slaves in urban manufacture as artisans, for example in the silk industry, and manumitted slaves as businessmen, traders, brokers and fiscal agents enabled the private household to become a socio-economic enterprise. Unlike that for workers of free status, the slave-owner relation ensured total dependency and a permanent social hierarchical structure. The price of a slave, although substantial, was equivalent to a couple of years’ wages of a regular employee in both Spain and the Ottoman Empire. Investing in a household slave thus gave the owner a worker for life, for whom he paid the equivalent of a two years’ wages plus expenses, and whom he could later free (in Ottoman society normally after 7–10 years) and use as both an agent and a member of the extended family. This socio-economic reasoning stood in contrast to the new notion of “wage labor” as it was conceptualized and practiced in northwestern Europe following the industrial revolution.
(Source: “Forms of Slavery in Mediterranean History”, by Youval Rotman, 2014)
The Use of Slaves in the Byzantine World
Among the four major sources of slaves—war, commerce, breeding, and selling of oneself into slavery— two concern the international arena: war and commerce. War had been a major generator of slavery in ancient times, and continued to be prevalent in Late Antiquity. It was complemented by a large importation of slaves. Roman sources reveal a worldwide trafficking in slaves that were imported to the empire from Ethiopia, India and the Caucasus.
This trafficking depended, of course, on the fortune and wealth of the Roman Mediterranean societies. The geopolitical map of the Romano-Byzantine Empire was radically transformed in the seventh century with the loss to the Umayyad Caliphate of all of the Byzantine provinces in Asia and Africa, Asia Minor excepted: Palestine, Syria, Egypt, Mesopotamia and North Africa. The continuous wars between Byzantium and the Caliphate affected the entire geopolitical constellation of the eastern Mediterranean up until the arrival of the Crusades. In Antiquity war had been always a major source of slaves. However, thanks to the exchanges of prisoners of war between the two states, the wars between Byzantium and the Caliphate did not become a major provider of slaves to either side.
The introduction of this new international custom affected greatly the slave trade since prisoners of war were not sold automatically into slavery, but were held by the state in order to be used in a prospective exchange of captives. As stated in the Military Law (nomos stratiōtikos) captives are not considered as spoil, and should be guarded by the strategos and brought to Constantinople for a prospective exchange of prisoners of war.
The same was probably also the case in Byzantium’s military front in the Balkans as is attested in an inscription from 816, today at the Archaeological Museum in Sofia, which documents an exchange of prisoners of war between the Byzantines and the Bulgars “soul for soul” (psyche anti psyhes).
Trade thus became the major means of supplying the demand for foreign slaves in both Byzantium and the Caliphate.
The slave markets in the major cities of the Caliphate and Byzantium are well attested. The Patria of Constantinople, although a later source, provides a short description of the slave market of Constantinople.
Other major cities had probably also a place for human merchandise at the local markets although we are not informed about them in the sources that survive. In any case the circulation of slaves into the empire through Abydos and the Dodecanese islands is well attested for the end of the eighth century by Theophanes Confessor.
“Scythian” slaves, i.e. slaves whose origin is from the north of the Balkans, the Black Sea and eastern Europe, are mentioned in Byzantine sources of all kinds: historiographic, hagiographic, juridical and documentary.
Their use was not limited to domestic functions within the Byzantine household. They are mentioned as rural workers by the Farmer’s Law and the Fiscal Treatise found in the Bibliotheca Marciana, as well as by other documents.
Slaves are also mentioned in the urban commercial activities of tenth-century Constantinople, namely by The Book of the Prefect.
Starting from the seventh century, the Balkans and eastern Europe, namely the Slavic and Bulgar populations constituted the main source of slaves for Byzantium and for the Caliphate. Africa was also an important source of slaves for the Arab world, but African slaves were not enough to meet the demands of this world, which made a distinction between African and European slaves. The first were named ‘iba’d in al-Andalus, while the second were named saqaliba, after their origin: eastern Europe.
In fact, in ninth-tenth century Iraq, the same term, saqaliba, is used to designate generally the Slavs and the Bulgars alike.
This difference between African and European slaves, that is slaves from the Sub-Sahara in comparison to slaves from eastern Europe and the Caucasus, was in fact also economic since the second were more expensive. This can be explained by the long commercial itineraries that connected eastern Europe to the Arab markets.
The slave trade thus moved from north to south, and as far as the Arab world was concerned also from the south (Africa) to the north. The Slavs and the Bulgars appeared thus to be the main source of slaves for both Byzantium and the Arab world.
The Persian geographer Ibn Khurradâdhbih’s description reveals an international trafficking in slaves of which the source is central and eastern Europe, while the markets are in the south-east (Iraq). Constantinople is mentioned as a destination of the Radhaniyya in one of their itineraries, but only for the importation of spices. All other routes, in contrast, including those of the slave trade, do not pass through the Byzantine Empire, inspite of the fact that a large slave market existed in Constantinople. The itineraries of the Radhaniyya (These were Jewish merchants who traded in arms, pearls, fabrics, furs, spices and young slaves of both sexes) bypassed Byzantium. But, a quick glimpse at the map will show immediately that Byzantium is situated exactly between the source of slaves and their markets in the south-east.
The Byzantine Slave-Trade Policy
In contrast to other medieval states, Byzantium had a political continuity from Roman antiquity. This also meant a central economic control based in Constantinople since the fourth century. The imperial control of trade took the form of taxes—kommerkia, handled by officials, kommerkiarioi, who were responsible for their collection. This system enabled the Byzantine state to control not only the circulation of merchandise in the empire, but thanks to the position of the Byzantine seaports, also the international commercial circulation between the three Byzantine seas: the Black Sea, the Aegean and the Adriatic.
Another aspect of the Byzantine control was juridical regulations on maritime transfer of merchandise. Such regulations are found in The Rhodian Sea Law (Nomos Rhodion Nautikos), which mentions human merchandise.
Slaves, who were dispatched by ships, were placed under the responsibility of the ship captain. The particularity of human merchandise was its potential escape, in which case the regulations stated that the captain was made responsible to reimburse their value to their owner. We are particularly informed about the Byzantine control of the slave trade by a description of Theophanes Confessor: in 801 the empress Irene reduced the taxes on all merchandise imported, to win over public opinion which was hostile to her coup d’état. Eight years later Nikephoros I restored the taxes and introduced a special measure concerning specifically the slave trade: all slaves who did not pass through the customs at Abydos were subject to a new tax of two nomismata per slave. This was ten percent of the average price of a slave in Byzantium. Theophanes Confessor added that this measure was aimed for slaves who were normally passed through the Dodecanese islands.
We can draw a connection between this and the description of Ibn Khurradâdhbih, and argue that the Radhaniyya made their huge detour in order to avoid Byzantine customs. The same Ibn Khurradâdhbih mentions the dime which the Russian merchants had to pay to the Byzantine authorities when passing from the Black Sea to the Mediterranean.
A dime was a serious sum for a slave ship, and the Radhaniyya preferred therefore to stop at Antioch, which was the nearest seaport in the ninth centuryto the south of the Byzantine border, rather than to pass via the Aegean Sea, or Constantinople.
If we examine the taxes on international commerce in the Caliphate for comparison, we note that in the eighth century ‘Umar II (717–720) prohibited taxes on trade in order to encourage international commercial activities. A century later a text of Abu ‘Ubaid al-Qasim ibn Sallam mentions fiscal regulations of ‘Umar I ibn al-Khattâb (634‒644): it states that Muslim merchants paid a tax of two and a half percent, dhimmi
paid a tax of five percent, while foreign Byzantines (Rum) needed to pay ten percent “since they take the same percentage of foreign merchants who pass through their territories.” Although these regulations are attributed to the seventh century, they most probably reflect the reality ofthe time of the mid-ninth century author.
The Byzantine customs system of the eighth-ninth centuries, therefore, resulted not only in the control of the trading routes between the Aegean, the Adriatic and the Black Sea, but de facto also created a certain monopoly on the slave trade in the eastern Mediterranean. From an Arab middle-eastern point of view, the main source of European slaves, eastern Europe, was the hinterland of Byzantium. For the Byzantines there were itineraries in the Balkans and Black Sea to import slaves directly from eastern Europe. But for the Caliphate, there were no direct routes.
The Byzantine customs system functioned as a commercial barrier and forced the merchants who aimed at the Arab markets to take different itineraries detouring Byzantine lands and seas altogether.
We note that the same Byzantine rationale characterized the commercial activities in the Black Sea. The Byzantine control of the seaport of Trebizond oriented the trafficking in slaves between the Rus’ and the Arabs further to the east: to the Caspian Sea and Transoxiana.
We thus see that on the international commercial map Byzantium represented the main slave market outside of the Arab world. The Byzantines were in fact in competition with the Caliphate over this merchandise. The middle-eastern markets of the Arab world, which were not satisfied with the supply of African slaves, imported European slaves by using itineraries bypassing the Byzantine Empire: to the east, through the Caucasus and the Caspian Sea, and to the west by using trade roads leading from Raffelstätten to Spain via the Carolingian realm.
Although the Byzantine customs restrictions were not explicitly directed against slave traders from the Arab world, their effect was to create a barrier against commercial competition from this quarter. Byzantine policy in Italy further indicates that the government’s objective was to protect the domestic slave market against competitors.
A new Byzantine commercial policy started at the beginning of the tenth century with the treaties that Byzantium signed with the Rus’. These treaties gave a solid economic position to the Rus’ traders in Byzantium. The two treaties of 907, 911 and that of 944 granted them commercial concessions.
They received permission to enter the Byzantine markets, including Constantinople. No
tax is mentioned in the treaties. Moreover, the Byzantines undertook the accommodation of the Rus’ merchants and the protection of their ships against piracy. In fact, this was the commercial side of a military alliance, since the Rus’ also participated in the first half of the tenth century in Byzantine military expeditions, including the Byzantine expedition to get back the island of Crete.
This military alliance, which did not last, proved itself more important in the Black Sea.
In regards to the slave trade, these treaties reveal the Rus’ merchants as the main suppliers of slaves to the Byzantine markets. In fact, slaves are the only merchandise mentioned.
The Ruso-Byzantine treaties also mention piracy. In this respect, the treaty of 911 is specifically revealing since it sets an important diplomatic innovation. It contains a clause stating that anyone who encounters a man of the allied camp who has been abducted or held captive, should ransom him and shall send him to his native land. The ransomed captive will then reimburse his redeemer. By including this clause in the treaty, the two sides decided to form a joint front against piracy and the abduction of their subjects. In the tenth century piracy was a main threat to the freedom of Byzantine inhabitants. Byzantium responded to it in the Black Sea by using its political-commercial treaties with the Rus’, and at the same time by using Venice in the Adriatic.
(Source: “The Medieval Mediterranean Slave Trade”, by Youval Rotman, 2016)
Research-Selection for NovoScriptorium: Anastasius Philoponus