When Sultan Mehmet the Conqueror took Constantinople in 1453, he first ordered the construction of a new residence. This was to become the palace later known as Topkapi. The palace would remain the imperial enclave of the Ottoman sultans for 4 centuries, from 1465 to 1853. Over the years the palace complex underwent constant modifications. Today the complex is made up of four main courtyards of increasing grandeur and many smaller buildings.