The mosque dates from 1391 and the complex consists of a medrese - now a public health centre, recognizable in its architecture, but no good for pictures - and a türbe or tomb). It is named after Sultan Beyazit I (1360-1403) "who founded the first centralized Ottoman state based on traditional Turkish and Muslim institutions and who stressed the need to extend Ottoman dominion in Anatolia." (Enc. Britt.), whose nickname was "Yıldırım" or "The Thunderbolt".