Topkapı Palace was the official and primary residence of the Ottoman Sultans for approximately 400 years (1465-1856) of their 624-year reign.
After the Conquest of Constantinople in 1453, Mehmet II ordered to built his palace in its present location on top of the ancient Byzantine ruins, meanwhile he spent some time during its construction at a smaller palace where there is the University of Istanbul today, in Bayezit square. Once they moved to Topkapi palace, the old one was called as "Old Palace" and Topkapi as the "New Palace". But local people called it as "Topkapi" which in Turkish means "Gate of Cannons" because of huge cannons displayed outside of its gates, those which were used during the Conquest.
The palace was a setting for state occasions and royal entertainments and is a major tourist attraction today, containing the most holy relics of the Muslim world such as the Prophet Muhammed's cloak and sword. Topkapı Palace is among those monuments belonging to the "Historic Areas of Istanbul", which became a UNESCO World Heritage Site in 1985, and is described in Criterion as "the best examples of ensembles of palaces of the Ottoman period.
The palace is a complex made up of four main courtyards and many smaller buildings. At the height of its existence as a royal residence, the palace was home to as many as 4,000 people, formerly covering a larger area with a long shoreline. The complex has been expanded over the centuries, with many renovations such as after the 1509 earthquake and 1665 fire. It held mosques, a hospital, bakeries, and a mint.
The palace complex has hundreds of rooms and chambers, but only the most important are accessible to the public today. The complex is guarded by officials of the ministry as well as armed guards of the Turkish military. The palace is full of examples of Ottoman architecture and also contains large collections of porcelain, robes, weapons, shields, armor, Ottoman miniatures, Islamic calligraphic manuscripts and murals, as well as a display of Ottoman treasure and jewelry.
Topkapı e was converted to a museum in 1924. Parts of the Palace such as the Harem, Baghdat Pavilion, Revan Pavilion, Sofa Pavilion, and the Audiance Chamber distinguish themselves with their architectural assets,while in other sections artifacts are displayed which reflect the palace life. The museum also has collections from various donations and a library.