Syria had suffered terribly during the Persian wars. Cities changed hands from the Byzantines, to Jewish revolutionaries, to the Persians and back to the Empire again.
Massacres had created huge rifts among the population, while an eight-year occupation had distanced the sentiments of the people from the Empire. In parts of Syria the
“occupation lasted fifteen years, a whole generation up to and including young adults-in an era of short life-spans, perhaps half the total population-would never have experienced Byzantine rule at all”.
Long-standing religious divisions were still unresolved. The economy was in shambles after being the frontline in a 50-year war. Matters were so grave that Heraclius spent the first three years after his victory on a whistle-stop style tour of Syria trying to reconstruct the Imperial apparatus and eliminate corruption.
Despite this intense focus on reconstructing Syria, somehow the Byzantine administration made some grave oversights regarding Syria during this time. First, no further attempt was made to reconcile the Monophysite faith with Orthodoxy. Secondly, the professional army was withdrawn from Syria to support a new campaign in the Balkans. Third, and most grave, the Byzantines quit paying the subsidy to the Ghassinid Arabs.
The Ghassinid tribe had been loyal allies of the Empire for centuries. Originally these Arabs had prospered on the Frankincense trade in southern Syria, but they had slowly become an almost exclusively mercenary outfit supporting the Empire with intelligence about Persia and events in the Arabian deserts. The Ghassinids had become Christian (Monophysite of course) and had received many Byzantine titles and gifts. The Ghassinids had even provided part of the invading force into Persia. In 629 AD the Ghassinids fought and won a brutal battle against a new threat, a large religiously motivated army from the Arabian Peninsula. This encounter, near the town of Mu’ta was the first conflict between the Muslims and Byzantium. Despite the long-standing relationship, strategic placement and loyal support, the money was cut off in 630 AD. In one stroke, the Empire lost a buffer against an unknown enemy, lost its intelligence capability and a standing army in southern Syria, and irritated a powerful group of warriors. It was a diplomatic blunder of unprecedented scale and would cost the Empire dearly.
(Source: ARAB-BYZANTINE WAR 629-644 AD, by LCDR David Kunselman)
Research-Selection for NovoScriptorium: Anastasius Philoponus