The eastern roman empire capital of byzantium received a name change after a famous emperor's death. the new name became
constantine
istanbul
constantinople
ankara

The correct answer is: "Constantinople".

Constantinople was the capital of the Eastern Roman or Byzantine Empire, and afterwards of the whole Roman Empire (its remainings), until it ended up falling under the dominance of the Ottomans in 1453.

The city was reinaugurated in year 324, from former Byzantium, and baptized again, after the name of the Emperor Constantine the Great. It became the new capital of the Roman Empire in 330.

after the roman empire, the catholic church began to unify by taking on many duties of a government.