Which city was the largest and wealthiest city in Europe from the mid-5th century to the early 13th century?

Constantinople was the capital city of the Roman Empire (330–395), the Byzantine Empire (395–1204 and 1261–1453), the brief Crusader state known as the Latin Empire (1204–1261), and the Ottoman Empire (1453–1922).

In 324, the ancient city of Byzantium was renamed “New Rome” and declared 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 opulent aristocratic palaces. The University of Constantinople was founded in the fifth century and contained 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 100,000 volumes.

The city was the home of the Ecumenical Patriarch of Constantinople and guardian of Christendom's holiest relics such as the Crown of thorns and the True Cross.