After the conquest of Istanbul by Sultan Mehmed II in 1453, his troops went looting through the capital of the fallen Byzantine Empire. That same afternoon, the sultan entered the Hagia Sophia, which was already more than 900 years old, and said his prayers. From then on, the church served not only as a mosque until 1935, but also as a model for the great Ottoman master builders. A good 150 years after the conquest, Sultan Ahmed I had the Blue Mosque built opposite the Hagia Sophia. Between the two buildings is the Sultan Ahmed Park with a fountain in its centre. In fine weather, this is a popular place to meet and enjoy life.