A titular see of Lydia, suffragan of Sardis. This town is mentioned by Ptolemy (VI, ii, 16). Judging from its coins it worshipped Artemis Persica. The site of Hierocæsarea must have been between the villages of Beyova and Sasova, seven or eight miles south-east of Thyatira, on the left bank of the Koum-Chai, a tributary of the Hermus, and in the vilayet of Smyrna. It is mentioned as an episcopal see in all the "Notitiæ Episcopatuum" until the twelfth or thirteenth century, but we know only three of its bishops: Cosinius, at Chalcedon, 451; Zacharias, at Nicæa, 782; Theodore, at Constantinople, 879.
RAMSAY, Asia Minor, 128; LEQUIEN, Or. Christ., I, 891; FOUCART in Bulletin de correspondance hellénique, XI (1887), 93 sqq.