Emperor Augustus, r 27 BC-14 AD, established a Roman navy base, controlling the Adriatic Sea and eastern Mediterranean, at the port of Classe, just south of Ravenna.  Silting rendered the port unusable by the 5th C.

2nd C martyrdom of Vitalis in Ravenna.

2nd C Ravenna converted to Christianity by patron saint, Apollinare.

325 AD Emperor Constantine the Great convened the Nicene Council to confirm his control of the church , develop the Nicene creed- a uniform set of Christian beliefs, and declare Arian Christianity-doubting that Jesus was divine-a heresy.

402 AD Emperor Honorius of Western Roman Empire moved the capital from Milan to Ravenna.

423 AD Emperor Honorius died and his half-sister Galla Placidia, now Augusta, with her 6 year old son Valentinian, now made Caesar, left Constantinople to claim control of the Western Roman Empire.

476 AD Ravenna conquered by Hungarian Ostrogoths.

493 AD to 526 AD under Gothic King Theodoric, Ravenna prospered, the largest city in Italy.

500 AD Theodoric built the Arian Palace Church, converted to a Christian church in 560 under Byzantine rule, renamed in 856 as Basilica of San Apollinare Nuovo.

523 AD Justinian married Theodora.  Four years later they would co-rule the Easter Roman Empire.

526 AD Theodoric built the Arian Baptistery where baptism of pagans was performed under the vaulted mosaic of Jesus being baptised by John the Baptist.  Prior to taking Ravenna the Goths had been converted to Arianism by Bishop Ulfilas, sent as a missionary in the mid 4th C by Bishop Eusebius of Nicomedia who was an Arian sympathizer in spite of belonging to the court of Constantine the Great.

527 AD Justinian became Emperor of the Eastern Roman Empire, capital Constantinople, till his death in 565 AD.

532 AD Commissioned by Bishop Ursus, the Basilica of San Apollinare in Classe was consecrated in 549 AD by Bishop Maximian.

540 AD General Belasarius took Ravenna for Emperor Justinian of the Eastern Roman Empire. Ravenna was a showcase for Byzantine art and culture for the following 200 years.

547 AD Basilica of San Vitale consecrated.

549 AD Basilica of San Apollinare in Classe consecrated.

752 AD  Germanic Lombards invaded northern Italy, beginning the decline of Ravenna.

1441 AD Ravenna under Venetian, then Papal rule.