The Beyazit II Mosque (Turkish: Beyazit Camii, Beyazit Camii) is an Ottoman imperial mosque located in the Beyazit Square area of Istanbul, Turkey, near the ruins of the Forum of Theodosius of ancient Constantinople.
The Beyazit Camii was commissioned by Ottoman Sultan Bayezid II, and was the second large imperial mosque complex to be erected in Istanbul after the Conquest. As the earliest complex, the Fatih Mosque was subsequently destroyed by earthquakes and completely rebuilt in a different style, the Beyazidye complex is thus of considerable historical and architectural significance. Little is known about the architect other than that he also built a caravansary in Bursa; however, the polished style of the mosque itself indicates experience with earlier Ottoman and western architectural techniques. The surrounding kulliye complex (madrasah, primary school, imaret (public kitchen) and hammam), date from 1501 to 1506.The dome was partially rebuilt after an earthquake in 1509, and Mimar Sinan conducted further repairs in 1573–74. The minarets burned separately in 1683 and 1764. An inscription above the courtyard entrance suggests that repairs were also conducted in 1767.
The mosque is oriented along the northwest-southeast axis with a courtyard to the northwest with an area almost equal to that of the mosque itself. the courtyard has monumental entrance portals on each side. The courtyard is a colonnaded peristyle, with twenty ancient columns of porphiri, verd antique and granite salvaged from churches and ancient ruins, roofed with 24 small domes, and with a pavement in polychrome marble.The mosque itself is approximately 40 meters square, with a 17 meter diameter dome. The design is that of a central dome held by semi-domes on all four sides. The mosque is constructed entirely of cut stone appropriating colored stones and marbles appropriated from nearby Byzantine ruins.
The interior of the mosque is patterned after the Hagia Sophia on a smaller scale. In addition to the huge central dome, semidomes to the east and west form a nave, whereas to the north and south extend side aisles, each with four small domes which extend the length of the mosque, but which are not divided into galleries. The dome is supported by huge rectangular piers, with smooth pendentives and stalactite decorations. The space is lit with twenty windows at the base of the dome and seven windows on each semi-dome, in addition to two tiers of windows on the walls.
On the west side, a broad extended corridor extends considerable beyond the main structure of the building. Originally designed as four domed rooms to serve as a hospice for wandering dervishes, the wings were integrated into the prayer hall sometime during the sixteenth century and now consist of three consecutive rooms separated by archways. At the ends of these wings are the two minarets.