Some history of Ravenna

From 402 AC until that empire collapsed in 476 it was the capital city of the Western Roman Empire

From 476 until 540 AC Ravenna served as the capital of the Kingdom of the Ostrogoths .

In 540 it was re-conquered by the Eastern Roman (Byzantine) Empire.

From 540 to 751 AD the city formed the centre of the Byzantine Exarchate of Ravenna

In 751 was the invasion of the Lombards after which it became the seat of the Kingdom of the Lombards.

Ravenna under Theoderic (a Wikipedia excerpt)

Theoderic took Ravenna in 493, supposedly slew his predecessor Odoacer with his own hands, and Ravenna became the capital of the Ostrogothic Kingdom of Italy.

Theoderic built many splendid buildings in and around Ravenna, including his palace church Sant'Apollinare Nuovo, an Arian cathedral (now Santo Spirito) and Baptistery, and his own Mausoleum just outside the walls.

The Mausoleum of Theoderic.

A multi-cultural society

Theoderic allowed Roman citizens within his kingdom to be subject to Roman law and the Roman judicial system.

The Goths, meanwhile, lived under their own laws and customs

In 519, when a mob had burned down the synagogues of Ravenna, Theoderic ordered the town to rebuild them at its own expense.

Both Odoacer and Theoderic and their followers were Arian Christians, but co-existed peacefully with the Latins, who were largely Orthodox.

What was the situation of the Roman Empire?

Even before Rome was sacked in 410 AC, the king had already moved to Ravenna, to be safe.

Ravenna had become the capital of the Western Roman Empire.

Constantinople (today Istanbul in Turkey) was the capital of the Eastern Roman Empire, also called Byzantine Empire.

Even though each empire had a separate ruler, it was still considered ONE empire. It was considered too big to be ruled together.

The Western Roman Empire "ended" in 476 AD and the Ostrogothic Kingdom reigned instead.

Theoderic the Great was the ruler of Italy from 493–526 .Theodoric sought to revive Roman culture and government and in doing so, profited the Italian people. Justinian I was the ruler of the Byzantine Empire, living in Constantinople.

Theodoric's leadership was not a barbarian but a civilized power. His twofold position ran through everything.

He reigned over a multi-cultural population: the Goths and other Germanic tribes, then the large population of indigenous Romans and many smaller groups, for example the Jewish population.

He did so without any imperial titles of the West Roman emperors. The two nations, differing in manners, language and religion, lived side by side on the soil of Italy; each was ruled according to its own law, by the prince who was, in his two separate characters, the common sovereign of both.

Where they all Christians?

Theoderic was an Arian Christian, whereas Justinian was an orthodox (Nicaean) Christian.
While Theoderic allowed both faiths and more, Justinian pushed to eradicate and destroy all other religions and faiths that were not orthodox. He punished and persecuted such people.
After Theoderic's reign finally a Western Roman Emperor would be established again and the orthodox Christian faith would override everything else.

Otis Art History 10 - Early Christian Byzantine

Early Christian Art into the Byzantine Hagia Sofia by Kenney Mencher