The Ulu Cami (Great Mosque) or Cami-i Kebir was built by the Danişmend ruler Melik Mehmed Gazi (1134-1143) and is one of the oldest mosques of Turkey. It was built on the spot of an earlier Byzantine church, from which some stone work was re-used. The ruins of the accompanying medrese (Kuran school) were removed in 1964 and turned into a parking zone.
The mosque underwent several restorations: in 1205 for the first time, in 1856 for the last.

On the picture: The eastern entrance to the prayer hall, and the ‘şadırvan’ (fountain for ritual ablutions) under a gallery in Classical Ottoman style (19th century).

Danişmend = Turkmen dynasty that ruled in north-central and eastern Anatolia from 1080 to 1178. The dynasty centered originally around Sivas, Tokat, and Niksar; they extended as far west as Ankara and Kastamonu for a time, and as far south as Malatya, which they captured in 1103. In early 12th century, Danişmend were rivals of the Seljuk Sultanate of Rum, which controlled much of the territory surrounding the Danişmend lands, and they fought extensively with the Crusaders.

Kayseri shifted from Byzantine to Danişmend rule in 1084, and stayed in their possession for almost a century, until 1178.

Correspondent: J.M.Criel, Antwerpen
Sources: ‘Tarihi Kayseri Cami ve Mescidleri’ – Doç. Ilhan Özkeçeci (1997), Wikipedia
& Personal visits (several times, last in 2001) .