Constantinople (Greek: Κωνσταντινούπολις, translit. Kōnstantinoúpolis (pronunciation ); Latin : Cōnstantīnopolis) was the capital city of the Roman Empire (330–395), of the Eastern Roman (Byzantine) Empire (395–1204 and 1261–1453), of the brief Crusader state known as the Latin Empire (1204–1261) and of the Ottoman Empire (1453–1923). In 1923 the capital of Turkey, the successor state of the Ottoman Empire, was moved to Ankara and the name Constantinople was officially changed to Istanbul ; the city is still referred to as Constantinople in Greek-speaking sources. The city is located in what is now the European side and the core of modern Istanbul.
In 324 ancient Byzantium became the new capital of the Roman Empire by Emperor Constantine the Great, after whom it was renamed, and dedicated on 11 May 330. From the mid-5th century to the early 13th century, Constantinople was the largest and wealthiest city in Europe. The city became famous for its architectural masterpieces, such as Hagia Sophia, the cathedral of the Eastern Orthodox Church, which served as the seat of the Ecumenical Patriarchate, the sacred Imperial Palace where the Emperors lived, the Galata Tower, the Hippodrome, the Golden Gate of the Land Walls, and the opulent aristocratic palaces lining the arcaded avenues and squares. The University of Constantinople was founded in the fifth century and contained numerous artistic and literary treasures before it was sacked in 1204 and 1453, including its vast Imperial Library which contained the remnants of the Library of Alexandria and had over 100,000 volumes of ancient texts. It was instrumental in the advancement of Christianity during Roman and Byzantine times as the home of the Ecumenical Patriarch of Constantinople and as the guardian of Christendom's holiest relics such as the Crown of thorns and the True Cross.
Constantinople was famed for its massive and complex defences.
