The name Constantinopolis came after him. It was often just referred as polis. The name Istanbul is derived from "eis tan polis" (to the city) used as a common phrase during Byzantian times. Turks kept using this old names as Konstantiniyye (Constantin's city in Arabic) Istanbul, both only referring to the walled part of the city till mid-20th century.
The name Constantinopolis came after him. It was often just referred as polis. The name Istanbul is derived from "eis tan polis" (to the city) used as a common phrase during Byzantian times. Turks kept using this old names as Konstantiniyye (Constantin's city in Arabic) Istanbul, both only referring to the walled part of the city till mid-20th century.