not a *titular* see in the 5th century!
Through the following centuries, the town shared its fortunes with Byzantium as it saw the passing of the Persians under Darius and allied itself at times with Athens and Sparta. In the first century before Christ it came into the hands of the Romans when king Nicomedes of Bithynia willed the area to them upon his death. Overshadowed by the proximity of Constantinople, as Byzantium was renamed after [[Constantine the Great|Constantine I]]’s death, the city was often used as a source of building stone for the monuments of the Eastern Roman capital.
In 361, Chalcedon was the site of the tribunal of [[Julian the Apostate]] where he brought his enemies to trial. The city was a
titular [[see]] that became famous as the site of the [[Fourth Ecumenical Council]] in 451. The council was held at a magnificent church that was situated of the hill at Haider Pasha. This church was later destroyed by Suleiman when he had his mosque built in Constantinople.
In the seventh century, Chalcedon was held captive by the Persian forces of Chosroes II<ref>Gibbon. ''Decline, &c.'' 100.46.</ref> and those of the Arabs of Yazd.