Thema

During the late sixth and early seventh centuries AD, the Byzantine Empire was under assault. The Persian Empire was pressing it from the south and east, assaulting Syria, Egypt, and Anatolia. Slavs and Avars raided Greece and disputed the Balkan holdings of the Eastern Roman Empire. The Langobards freely raided northern Italy, completely unopposed. The treasury of the Empire was drained and its generals were in open rebellion. Under such circumstance, Heraclius ascended to the throne and instituted the reforms that would serve as the backbone of the Empire for generations to come.

The reorganizations of Heraclius were sorely needed, as is evident. With wars being waged simultaneously in the east and the west, the public coffers were all but empty. Furthermore, the empire was relying substantially on mercenaries to fight its wars, a sure sign of weakness. The basic objective of Heraclius’s alterations was to return the military to the Republican system of landed citizen armies. In order to do this, Heraclius began distributing land to the armies and the individual soldiers in exchange for hereditary military duty at a reduced expense to the state.

A Thema was a plot of land given to the soldiers to farm. They were still technically a military unit, under the command of a Strategos, a military and civil authority. The soldiers did not technically own the land they worked. It was still controlled by the state, and therefore for its use the Soldier’s pay was reduced. Furthermore, by accepting this proposition, the participant agreed that his descendants would also serve in the military and work in a Thema, thus simultaneously reducing the need for unpopular drafts as well as cheaply expanding the military. It also allowed for the settling of conquered lands because these Themes could be rapidly formed into military units and there was always a substantial addition made to public lands during a conquest.

This system of transplanting military units into unsettled lands and creating an inherent loyalty to the state, something every government has struggled with, greatly strengthened the Byzantine Empire. Over the next several decades, the Persians were routed and their empire ceased to exist, the Slavs and Avars were reduced and rebellions within the empire became far less common. The Themes military structure rescued the Eastern Roman Empire from destruction and gave it a durability that would last for centuries to come.