The Empire of Byzantium was the eastern portion of the Roman Empire, which was divided in 395 A.D. Its stable economy provided a strong military and, together with an abundant food supply and advanced civil engineering, a high standard of living.
The empire saw a period of cultural, territorial and economic advances in the 10th and 11th centuries. Towards the end of the 11th century, the empire started to isolate itself culturally, while Europe states and the Muslim world made new advances in fields of science, military and economics.
At the beginning of the Komnenian period in 1081, the Byzantine Empire had been reduced to the smallest territorial extent in its history. Surrounded by enemies, and financially ruined by a long period of civil war, the empire's prospects had looked grim. Yet, through a combination of determination, military reform, and years of campaigning, Alexios I Komnenos, John II Komnenos and Manuel I Komnenos managed to restore the power of the Byzantine Empire.
Agriculture was the backbone to the economy but oppressive taxation and frequent disruptive power struggles ( not to mention almost constant war against invaders) and the devastation of whole areas by Jidhadi Ghasi Muslim raiders and slavers and the eventual conquest of the whole of the Empire by the Turks greatly hindered their economic life.
Also there is considerable evidence that the empire's population expanded steadily during the period covered by this book, and that agricultural production was intensified. A wealth of evidence serves to reinforce the point that the disintegration of the empire in the late twelvth century should no longer be associated with economic decline.
The Byzantine Empire's economy relied on trade and farming. The richest, the biggest and the most populous cities-ports were in the West and North coast of Asia Minor. Some of these cities were Trebizond, Sinope, Smyrna, Nikaia, Nikomedia, Ephesus and so on. Also the west Asia Minor was full of plains and rivers and it was good for farming. I don't think that the eastern provinces provided anything for the economy, because it was mostly a mountainous area and was scarcely populated. They were just contributing to the thematic defense, and the garrison of the borders with Acritae.
Certain provinces, or parts of provinces such as northern Italy, flourished commercially as well as agriculturally. Constantinople, in particular, influenced urban growth and the exploitation of agricultural frontiers. Balkan towns along the roads leading to the great city prospered, while others not so favoured languished and even disappeared. Untilled land in the hilly regions of northern Syria fell under the plow to supply foodstuffs for the masses of Constantinople.
Byzantium remained the most stable nation of the middle ages. Its central location between western Europe and Asia not only enriched its economy and its culture but allowed it to serve as a barrier against aggressive barbarians from both areas.