The mosque was to be built on the site of the palace of the Byzantine emperors, facing the Hagia Sophia (at that time it was most venerated mosque in Istanbul) and the hippodrome, a site of great symbolic significance. Large parts of the southern side of the mosque rest on the foundation and vaults of the Great Palace. Several palaces was already built there, most notably the palace of Sokollu Mehmet Pasha, so these first had to be bought at a considerable cost and pulled down. Large parts of the Sphendone (curved tribune with U-shaped structure of the hippodrome) were also removed to make room for the new mosque. Construction of the mosque started in August 1609 when the sultan himself came to break the first sod. It was his intention that this would become the first mosque of his empire.