The King's Road from Ephesus passed through Gordion, Ankara, Çorum, Tokat and Sivas, from where it continued eastwards into Iran. Successive civilisations which ruled the region grew wealthy on the busy trade, and attached importance to maintenance of the roads and keeping them secure. During Seljuk and Ottoman times numerous bridges were built over rivers on the roads leading to the Gulf of Basra, eastern Anatolia, the Black Sea and Konya. Some of these bridges can still be seen today, such as the Egri, Kesik, Bogaz and Kizilirmak bridges.
Sivas was invaded during the Arab incursions of the 7th and 8th centuries, and conquered by the Turkish general Emir Danismend Gazi in 1071. The Danismendogullari principality ruled the city until 1175, after which it became part of the Anatolian Seljuk State. It was at this time that the city walls, castle, Ulu Mosque, and other monumental works of Seljuk architecture were constructed. At Divrigi east of Sivas the Mengucekogullari principality built the superb monuments for which this town is renowned: Kale Mosque built by Sahin Sah, Ulu Mosque by Ahmed Sah, and the hospital by Melike Turan Melek.