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. Roman civilization first made contact with this territory during the 3rd century BC. Julius Caesar gathered his forces at this location in 49 BC before crossing the Rubicon River. Octavian founded the military harbor known as Classis after defeating Mark Antony in 31 BC. This harbor became an important station for the Roman Imperial Fleet and remained protected by its own walls. The city prospered under imperial rule, with Emperor Trajan building a long aqueduct at the beginning of the 2nd century. Marcus Aurelius banished Germanic settlers who had revolted during the Marcomannic Wars.
Imperial Capital Of The West
Emperor Honorius moved his court from Mediolanum to Ravenna in 402 AD. The transfer served defensive purposes because swamps surrounded the city and made it easily defensible. It also provided good sea-borne connections to the Eastern Roman Empire. The last de facto western emperor Romulus Augustulus was deposed there in 476. At that time, the city housed approximately 50,000 people. King Alaric I of the Visigoths bypassed Ravenna in 409 to sack Rome instead. Galla Placidia returned to the city with her son Valentinian III after receiving support from her nephew Theodosius II. The imperial court favored Christianity during this period of peace. The city gained famous monuments including the Orthodox Baptistry and San Giovanni Evangelista.