A city of Lydia, in Asia Minor, a Macedonian colony, anciently called Pelopia and Euhippia, now Ak-hisar. It was situated on the confines of Lydia and Mysia, near the river Lycus, between Sardis and Pergamos. It was the seat of one of "the seven churches," Revelation 1:11; 2:18,24. The art of dyeing purple was particularly cultivated at Thyatira, as appears from an inscription recently found there; and it still sends to Smyrna, sixty miles southwest, large quantities of scarlet cloth, Acts 16:14. Ak-hissar is a poor town, with six thousand inhabitants, chiefly Turks.