Short answers, pulled from the story.
The Umbri people settled the marshy islands of what is now Ravenna by the 5th century BC. These early inhabitants built houses on wooden piles within a lagoon that resembled Venice centuries later.
Emperor Honorius moved his court from Mediolanum to Ravenna in 402 AD for defensive purposes because swamps surrounded the city and made it easily defensible. The transfer also provided good sea-borne connections to the Eastern Roman Empire.
General Belisarius conquered Ravenna for the Byzantine Empire in 540 under Emperor Justinian I. The city became the seat of Byzantine government in Italy following the completion of conquests in 554.
In 756, Aistulf conceded defeat and agreed to surrender the territory taken five years earlier. This act became known as the Donation of Pepin and provided legal basis for the creation of the Papal States.
The funeral ceremony of Dante Alighieri was held in 1321 at the church of San Francesco. Local authorities resisted all demands by Florence for the return of his remains for centuries.
Troops of the 4th Princess Louise Dragoon Guards entered and liberated Ravenna on the 5th of November 1944. Bombs intended for the railway station pulverized the Basilica of San Giovanni Evangelista in August 1944.