document dated October 1754 states that a special type of stone was brought from Karamürsel to repair the mosque. An inscription above the courtyard entrance suggests that repairs were also carried out in 1767 as a result of the earthquake which struck Istanbul in 1766. Extensive new restoration work was started in August 2012 and took eight years to complete. During the process inappropriate materials used during previous repairs were removed, and damaged materials were either cleaned or replaced. The restoration involved a team of approximately 150 people and cost 49 million Turkish liras (approximately US $7.2 million). The mosque was reopened for worship in 2020. Architecture Exterior 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 three sides and is surrounded by a colonnaded peristyle supported by twenty columns. Two of the columns are made of porphyry, ten are of verd antique, and six are of pink granite. It is roofed with 24 small domes and has a pavement of polychrome marble. The mosque itself is square measuring approximately per side and its dome is approximately in diameter. The central dome is supported by two semi-domes along the main axis and two arches running along the secondary axis. The mosque is constructed entirely of cut stone using coloured stones and marbles. Interior The mosque interior resembles a smaller scale version of the Hagia Sophia. In addition to the central dome, the semi-domes to the east and west form a nave. To the north and south there are side aisles, each with four small domes, which extend the width 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. An elevated sultan's loge (hünkâr mahfili), located to the right of the mihrab, is supported by ten small marble columns which were reused from earlier Byzantine churches. On the west side, a broad extended corridor extends considerably beyond the main structure of the building. Originally designed as four domed cells to serve as a hospice for wandering dervishes, the wings were integrated into the prayer