The Topkapi Palace was the primary residence of the Ottoman Sultans for nearly 400 years. It was built in the 15th century by the Ottoman sultan Mehmed II, also known as Mehmed the Conqueror after he conquered Constantinople (present-day Istanbul) in 1453. 

The palace was designed as a fortified compound with multiple buildings, gardens, and courtyards and served as the centre of Ottoman political and social life. 

It was also a symbol of Ottoman power and wealth, filled with treasures and works of art worldwide. The palace continued to be used as the primary residence of the Ottoman sultans until the mid-19th century when it was converted into a museum. 

Today, the Topkapi Palace is a significant tourist attraction in Istanbul and is a UNESCO World Heritage Site.