Justinian’s Italian reconquest left a ruined pyrrhic prize
From 535 to 554 Justinian’s Byzantium fought the Ostrogoths across Italy, Dalmatia, and the western islands—the last Gothic war with the empire. Belisarius opened the first phase after the swift Vandal conquest of Africa; a pragmatic sanction in 554 redesigned Italian government while some northern cities held until 562.
The war's roots lay in an arrangement that had worked well for a generation. Odoacer deposed Romulus Augustulus in 476, and when he grew too independent, Emperor Zeno sent Theodoric's Ostrogoths to remove him. Theodoric then governed Italy as the emperor's viceroy and army chief. Romans staffed the civil administration and lawmaking stayed with Constantinople, while the army was entirely Gothic. Religion divided the two groups, Chalcedonian Italians and Arian Goths, but the Goths were notably tolerant.
The balance frayed late in Theodoric's reign. As church unity returned in the East, Italian senators leaned toward Constantinople, and the execution of Boethius and his father-in-law in 524 marked the estrangement. Theodoric's grandson Athalaric inherited at ten in 526 under his Roman-educated mother Amalasuntha, whose overtures to the Senate angered Gothic nobles; she had three plotters killed and quietly asked Justinian for refuge. After Athalaric died in 534 she offered the crown to her cousin Theodahad, who arrested her, and she was killed early in 535. Justinian, fresh from Belisarius's startlingly quick conquest of Vandal Africa in 533, treated her death as grounds for war.
The fighting ran across Italy, Dalmatia, Sicily, Sardinia and Corsica. In the first phase Belisarius advanced until the Gothic capital Ravenna fell in 540. From 540 or 541 the Goths rallied under Totila, and only a long campaign by the general Narses put them down. In 554 the Byzantines also had to throw back a Frankish invasion, even though the Franks had been nominal allies while dealing secretly with the Goths.
Justinian issued a pragmatic sanction in 554 laying out how Italy would now be governed, though some northern cities resisted until 562. The prize was a wreck: Italy was ravaged and emptied of people. When the Lombards invaded in 568, Constantinople could not stop them and lost much of the peninsula for good, which is why historians describe the reconquest as a pyrrhic victory.
Source: Gothic War (535–554)
