The ‘Beyazıt Kapısı’ (Gate of Beyazıt, because of the nearby Beyazıt Mosque) is one of the eleven main entrances to the Grand Bazaar (in addition, there are eleven secondary gates and tenths of small escape doors, generally known by the shopkeepers and workshops’ artisans only). The calligraphy above the gate is the ‘tuğra’ of Abdülhamid II, who had the Covered Bazar restored in 1898 (after the 1894 earthquake).
A ‘tuğra’ is a calligraphic monogram, seal or signature of an Ottoman sultan, that was affixed to all official documents and correspondence.
Correspondent: J.M.Criel, Antwerpen.
Source: (amongst others) Vikipedia/Wikipedia ; numerous personal visits between 1978 and 2002
& Website of ‘placesinistanbul.com’ .