The Topkapı Palace (Turkish: Topkapı Sarayı or in Ottoman Turkish: طوپقپو سرايى) is a large palace in Istanbul, Turkey, that was the primary residence of the Ottoman Sultans for approximately 400 years (1465-1856) of their 624-year reign.
As well as a royal residence, the palace was a setting for state occasions and royal entertainments. It is now a major tourist attraction and contains important holy relics of the Muslim world, including Muhammed's cloak and sword. The Topkapı Palace is among the monuments contained within the "Historic Areas of Istanbul", which became a UNESCO World Heritage Site in 1985, and is described under UNESCO's criterion iv as "the best example[s] of ensembles of palaces [...] of the Ottoman period."
The palace complex consists of four main courtyards and many smaller buildings. At its peak, the palace was home to as many as 4,000 people, and covered a large area with a long shoreline. It contained mosques, a hospital, bakeries, and a mint. Construction began in 1459, ordered by Sultan Mehmed II, the conqueror of Byzantine Constantinople. It was originally called the New Palace (Yeni Sarayı) to distinguish it from the previous residence. It received the name "Topkapı" (Cannon Gate) in the 19th century, after a (now lost) gate and shore pavilion. The complex was expanded over the centuries, with major renovations after the 1509 earthquake and the 1665 fire.