The Mihrimah Sultan mosque was built for Mihrimah Sultan, daughter of Süleyman the Magnificent (1520-1566), as part of a complex that includes a madrasa, an infirmary, a school, and baths. On a sloping site along Iskele Square in Üskudar, the mosque has a rectangular plan aligned on the northeast-southwest axis.

It is entered from a portal on the northwest, the central bay of a five-bay portico. Surmounted by five domes, the open portico is carried by six columns along its northwest side. Running along the northwest side of the mosque is a secondary arcade, which is as deep as the portico and is carried over pointed arches resting on relatively slim columns. This arcade extends northwest to cover the circular fountain, which is on axis with the portal of the mosque. Made of marble, the portal carries an inscription with the construction date of 1547 that names Mihrimah Sultan and Süleyman the Magnificent as its patrons.

The Mihrimah Sultan is one of Sinan's early mosques, where he made a structural experiment, choosing to flank the main dome on three sides with three half-domes. This was the first time Sinan used half-domes, with the end result that the spatial organization and the structural system of the mosque are not perfectly resolved. The asymmetry in the structure entailed both a heavy structure and an unusual configuration on the southeast elevation, which ended abruptly. The portico was not adequate to overcome the effect of the southeast elevation, so another large arcade was added, which extended to cover the fountain. Another side effect of the asymmetrical design was the immediate entry into the prayer hall, which impaired the sense of spatial depth. However, this quick entry also created the opportunity for the visitor to experience all of the interior space simultaneously.

Above the prayer hall, the main dome has sixteen windows; the main dome and the three half-domes are supported with twin buttresses that appear on four sides of the exterior. The south and east corner bays of the prayer hall are surmounted with two smaller domes. The muezzin's platform (muezzin mahfili), which is carried over five piers, is articulated as a small square projection southwest of the entrance. The minbar is placed just across the muezzin's platform on the qibla wall, southwest of the mihrab. The mihrab itself is a marble niche with muqarnas carvings above. The interior space is adorned with painted ornamentation, and the upper windows, as well as the windows in the domes, are filled with stained glass. The mosque has two minarets on the north and west corners of the prayer hall, both with single balconies. They are entered from the first and fifth bays of the portico. Their balconies have balustrades with stonework carried over four rows of stalactite carvings.

Sinan never designed a second mosque with three domes, leaving the Mihrimah Sultan as the only example of its type. However, this exploration of structural configurations came to influence his later work.

Sources:

Bayrak, M. Orhan. Türkiye Tarihi Yerler Kilavuzu, 339. Istanbul: Inkilap Kitabevi, 1994. 339.

Egli, Hans G. Sinan: An Interpretation, 20-22.. Istanbul: Ege Yayinlari, 1997.

Goodwin, Godfrey. Sinan: Ottoman Architecture and its Values Today, 49. London: Saqi Books, 1993.

Sözen, Metin. Sinan: Architect of Ages, 121-126. Istanbul: Prepared under the auspices of the Turkish Ministry of Culture and Tourism, 1988.