The Süleymaniye Mosque is an Ottoman imperial mosque located on the Third Hill of Istanbul.. It is the largest mosque in the city, and one of the best-known sights of Istanbul. The mosque and its surrounding complex were built at the request of Sultan Suleiman the Magnificent, in the mid-16th century (5 decades before the Blue Mosque).
The mosque and its surrounding buildings were designed by Mimar Sinan (he died at 97), the most famous and talented of all imperial architects. Sinan's türbe (tomb) is just outside the mosque's walled garden, next to a disused medrese building.
The mosque was built between 1550 and 1557. Its setting and plan are particularly pleasing, featuring gardens and a three-sided forecourt with a central domed ablutions fountain. The four minarets with their 10 beautiful balconies are said to represent the fact that Süleyman was the fourth of the Osmanlı sultans to rule the city and the 10th sultan after the establishment of the empire.
In the garden behind the mosque is a terrace offering lovely views of the Golden Horn. The street underneath once housed the külliye's arasta (street of shops), which was built into the retaining wall of the terrace. Close by was a five-level mülazim (preparatory school).
The interior of the mosque is almost a square, 59 meters in length and 58 meters in width, forming a single vast space. The dome is flanked by semi-domes, and to the north and south arches with tympana-filled windows, supported by enormous porphyry monoliths. Sinan decided to make a radical architectural innovation to mask the huge north-south buttresses needed to support these central piers. He incorporated the buttresses into the walls of the building, with half projecting inside and half projecting outside, and then hid the projections by building colonnaded galleries. There is a single gallery inside the structure, and a two-story gallery outside.