The Church of the Holy Apostles (, Agioi Apostoloi; ), also known as the Imperial Polyándreion (imperial cemetery), was a Byzantine Eastern Orthodox church in Constantinople, capital of the Eastern Roman Empire. The first structure dated to the 4th century, though future emperors would add to and improve upon it. It was second in size and importance only to the Hagia Sophia among the great churches of the capital. When Constantinople fell to the Ottomans in 1453, the Holy Apostles briefly became the seat of the Ecumenical Patriarch of the Eastern Orthodox Church. Three years later the dilapidated edifice was abandoned, and the patriarchate was moved to the Theotokos Pammakaristos Church. In 1461, the church of the Holy Apostles was demolished by the Ottomans to make way for the Fatih Mosque. History The original church of the Holy Apostles was dedicated in about 330 by Constantine the Great, the founder of Constantinople, the new capital of the Roman Empire. The church was unfinished when Constantine died in 337, and it was completed by his son and successor Constantius II, who buried his father's remains there. The church was dedicated to the Twelve Apostles of Jesus, and it was the Emperor's intention to gather relics of all the Apostles in the church. However, only relics of Saint Andrew, Saint Luke and Saint Timothy (the latter two not members of the formal group known as the Twelve Apostles) were acquired, and in later centuries it came to be assumed that the church was dedicated to these three only. By the reign of the Emperor Justinian I, the church was no longer considered grand enough, and a new Church of the Holy Apostles was built on the same site. The historian Procopius attributes the rebuilding to Justinian, while the writer known as Pseudo-Codinus attributes it to the Empress Theodora. The new church was designed and built by the architects Anthemius of Tralles and Isidorus of Miletus, the same architects behind the rebuild of Hagia Sophia, and was consecrated on 28 June 550. The relics of Constantine and the three saints were re-installed in the new church, and a mausoleum for Justinian and his family was built at the end of its northern arm. For more than 700 years, the church of the Holy Apostles was the second most important church in Constantinople, after that of the Holy Wisdom (Hagia Sophia). But whereas the