The Gothic War between the Byzantine Empire during the reign of Emperor Justinian I and the Ostrogothic Kingdom of Italy took place from 535 until 554 in the Italian peninsula, Dalmatia, Sardinia, Sicily and Corsica. The war had its roots in the ambition of the East Roman Emperor Justinian I to recover the provinces of the former Western Roman Empire, which the Romans had lost to invading barbarian tribes in the previous century (the Migration Period).
The war followed the Byzantine reconquest of the province of Africa from the Vandals. Historians commonly divide the war into two phases:
In 554 Justinian promulgated the Pragmatic sanction which prescribed Italy's new government. Several cities in northern Italy held out against the Byzantines until 562. By the end of the war Italy had been devastated and depopulated. The Byzantines found themselves incapable of resisting an invasion by the Lombards in 568, which resulted in Constantinople permanently losing control over large parts of the Italian peninsula.