The Byzantine empire was a continuation of the Eastern Roman Empire, the contributions they continued was keeping to there ways. It survived the fall of the western fall of the roman empire and continued to exist for an additional years until it fell to the Ottoman Turks in 1453. During it's existence the empire was the most powerful in economical and cultural and military forces in Europe during it's time.
The Byzantine Empire kept they're traditional Greek practices as you can see from the picture. Christianity was also legalized by Constantine and became the official religion of the Byzantine empire.
