Originally built as a Christian Orthodox cathedral and used for centuries, Hagia Sophia was converted into a mosque by the Ottomans following their conquest of Constantinople in 1453. Mustafa Kemal Ataturk, Turkey's secularist leader, proclaimed it a museum in 1934. Today, it is a museum full of art treasures. Built between 672 and 685 as part of the Byzantine Empire's new capital city on the site now known as Istanbul, St. Sophia was originally named "The Holy Wisdom" and was dedicated to the glory of God. Over time, it came to be regarded as one of the most important churches in the world. In 1453, when the Ottoman Turks conquered Constantinople, they converted the church into a mosque because they believed that doing so would bring peace to their empire. During its years as a mosque, St. Sophia was completely remodeled on several occasions. The last major renovation was completed in 1844 under Sultan Abdülmecid I. The work cost approximately $1 million ($12.5 million in today's dollars) and was paid for using tax revenues from throughout the empire. The result was an elegant building with pure Turkish design elements containing some of the finest works of art of the era. It remains one of the largest synagogues in Europe today.