Answer
Drepanon, Bithynia was renamed Helenopolis in honor of Helena, the mother of Constantine the Great. The city was founded in the 1st century AD and was originally called Drepanon, which means "sickle" in Greek. It was located on the coast of the Black Sea and was an important port city. In the 4th century AD, the city was renamed Helenopolis in honor of Helena, the mother of Constantine the Great.