The Church of the Holy Apostles in Constantinople (modern Istanbul) was one of the most important churches in Christendom. Built by Constantine the Great and rebuilt by Emperor Justinian, the church was the burial place of the Byzantine Emperors and Patriarchs of Constantinople from the 4th century to the 11th century. At one time, the Church of the Holy Apostles held the relics of St. Andrew, St. Luke, St. Timothy, St. John Chrysostom and St. Gregory the Theologian. The Church of the Holy Apostles was ruthlessly plundered in the Crusades and later toppled by a severe earthquake. Today, almost nothing of the great church remains, and the Fatih Mosque was built over the site.