Cidyessus or Kidyessos (grc|Κιδύησσος) was a city of some importance, west of Ammonia in west-central ancient Phrygia, in the territory of the Setchanli Ova, or Mouse Plain; this large and fertile valley projects far into Phrygia Salutaris, but the city was in Phrygia Pacatiana.[1]
The old native name may have been Kydessos, though it is Kidyessos on its coins.[1] Modern scholars place its site near modern Çayhisar, Sinanpaşa district, Afyonkarahisar Province.
Three ancient bishops of the see of Cidyessus are mentioned in extant contemporary documents: Heraclius participated in the Council of Chalcedon in 451; Andreas in the Second Council of Nicaea in 787; and Thomas in the Photian Council of Constantinople (879).[2] [3]
The see is mentioned in Notitiæ episcopatuum, until the 12th or 13th century, as a suffragan of Laodicea, the capital of Phrygia Pacatiana.
No longer a residential bishopric, Cidyessus is today listed by the Catholic Church as a titular see.[4]