Dios Hieron (Lydia)
Dios Hieron was a town of ancient Lydia, in the upper valley of the Cayster River. The city became part of the Roman Republic and the Roman province of Asia with the annexation of the Kingdom of Pergamon. It also bore the name Diospolis, and was cited by the sixth century Byzantine geographer Stephanus of Byzantium under that name. It was renamed to Christopolis or Christoupolis in the 7th century and was known as Pyrgium or Pyrgion from the 12th century on. Pyrgion fell to the Turks in 1307, and became the capital of the beylik of Aydin. The town minted coins in antiquity, often with the inscription "Διοσιερειτων".
Its site is located near Birgi, Asiatic Turkey.Bishopric
The Roman Era city had an ancient Christian bishop and is attested as an episcopal see from at least 451. It was a suffragan of Ephesus, which it remained under until the late 12th century when it became a separate metropolis.
There are four known bishops from antiquity.
Today Dioshieron survives as titular see in the Roman Catholic Church, so far the see has never been assigned.
