How Constantinople, the“New Rome”, was dedicated to the Mother of God

On learning of the tyrannical measures taken by the Roman emperor Maximinus II Daza in the East against the Christians, Constantine raised a powerful army, guided by the sign of the victorious Cross, and, during a campaign against the barbarians in Pannonia (1), penetrated Licinius' territory (2) in 322. 

After an initial defeat at Andrinople, the tyrant retreated to Byzantium, before being definitively defeated at the battle of Chrysopolis on September 18, 324. The victorious Constantine, in the name of Christ and Truth, set about offering the reunited Roman Empire to the King of kings, and, like a new Apostle, proclaimed faith in the one God and in His Son incarnate for our salvation to the farthest reaches of East and West, from Mesopotamia to Great Britain. In an edict proclaimed throughout the Empire, he declared that God alone was to be considered the cause of his victories, and that he had been chosen by Providence to place himself at the service of good and truth. He urged all his subjects to follow his example, but without coercing anyone. 

To this new Christian empire, which was to last a thousand years, Constantine decided to give a new capital, and inspired by a divine sign, the pious emperor fixed his choice on the small city of Byzantium, which occupied a pivotal position between East and West. He himself marked the boundaries of the new city, and instructed the master builder, Euphrata, to spare no expense in endowing it with monuments and public thoroughfares surpassing all other cities in the world in glory and magnificence. 

When the city was founded on November 8, 324, Byzantium was named Constantinople and New Rome, and was subsequently dedicated to the Mother of God. Work was carried out with great haste, and on August 11, 330, the twenty-fifth anniversary of the emperor's reign, the inauguration of the new capital was celebrated with great pomp.

Source: Adapted from www.orthodoxie.com 

Pannonia is an ancient region of Central Europe, straddling present-day Austria, Hungary, Slovenia, Croatia, north-western Serbia and northern Bosnia-Herzegovina. Licinius was Roman emperor from 308 to 324. For most of his reign, he was the colleague and rival of Constantine I