A lot of major changes in the game came from shortcomings Byzantium players found and exploited (strait blocking, available rivals, available allies, available missions, military access exploits. It's unique Roman lineage, culture, longevity, and prestige makes almost any EU4 player reluctant to restore the once great eastern Roman empire.

It starts with the fabled city of Constantinople, once one of the largest and richest. Starting with only Steam one hu190gw and three provinces in Southern Greece, as well as Athens as a vassal, its rebirth begins under the shadow of the Ottomans. Byzantium is what remains of the Eastern Roman Empire, and along with Trebizond and Theodoro, the last remnants of the once mighty Roman Empire.