The city's old name was Dorylaion in Greek and Dorylaeum in Latin; Arab sources give it as Darauliya, Adruliya and Drusilya. In the ancient writers it is a Phrygian city at a crossroads of important routes, famous for its hot springs and grown rich on trade, and its founder is given as Doryleos of Eretria. It mattered especially under Byzantium, and the emperor Justinian is said to have had a summer palace here.
Where exactly it stood was settled in the 19th century. Travellers and scholars working in the region identified the site now called Şarhöyük, three kilometres north-east of Eskişehir on the north bank of the Porsuk, as ancient Dorylaion. It is a mound of medium size for central Anatolia — 17 metres high and 450 metres across.
