On March 12, 538, Witiges, King of the Ostrogoths, ended his siege of Rome, retreated to Ravenna, and left the city in the hands of victorious Byzantine General Belisarius. From the article:
"Wars of the Ostrogoths
489 to 553
Ostrogoths — versus — Odoacer's Kingdom of Italy, later the Eastern Empire
Rise of the Ostrogoths 489-493 Fall of the Ostrogoths 535-553
Aftermath of Gothic War 554-568
Rise of the Ostrogoths: 489-493
The rise of the Ostrogoth Kingdom of Italy was the work of Theodoric, king of the Ostrogoths. The Ostrogoths were in service to the Eastern Emperor, and so in 489, with the support of Constantinople, Theodoric led a large army of Ostrogoths to attack Odoacer's Kingdom of Italy. Although successful in most of his battles against Odoacer, Theodoric ultimately resorted to treachery in order to make himself sole ruler, by first making a peace treaty with and then killing his rival. In spite of this inauspicious start, the reign of Theodoric, which lasted from 493 until his death in 526 was extremely successful and prosperous. He kept peace in Italy, and made alliances with the Visigoth and Frankish kingdoms in Spain and France. Having grown up as a hostage in the court at Constantinople, he was highly civilized, thoroughly Roman in manner, and preserved the best institutions of the empire. Although he had conquered Italy with the help of the eastern Empire, he governed independently.
Fall of the Ostrogoths: 535-553
By 533 Belisarius, the great general of Justinian, had established peace on the eastern borders of the empire, and had also reconquered the Vandal Kingdom of North Africa. In an effort to restore the Roman empire to its old glory, Justinian sent an army to reconquer Italy from the Ostrogoths. His pretext for the invasion was the assassination of an heir to the throne of the Ostrogoths, who had been an ally of Constantinople. The wars that followed for the next fifteen years are known as the 'Gothic Wars' and were a disaster for Italy. Although the Imperial army, led by Justinian's famous general Belisarius, had early victories—first taking Sicily, Rhegium, and Rome, and then two years later, taking Ravenna, the Gothic capital,—the Ostrogoths did not surrender. Instead they raised Totila, to the throne and renewed their offensive against the conquerors. Much of the territory that was taken by Belisarius, was retaken by Totila as soon as the former was recalled to Constantinople. Finally Justinian sent another army against the Ostrogoths, and finally destroyed them, but not until much of Italy had been laid to waste, and may of its major towns depopulated.
Aftermath of Gothic War: 554-568
Worse yet, the ravages of the Gothic war left Italy vulnerable to invasion from other, less civilized Germanic tribes from the North. Shortly after the final victory of the Eastern Empire over the Goths, a large army of Franks and Alemanni descended on Northern Italy, but were driven back by Imperial forces. A decade later, however, all of Northern Italy fell to the Lombards, a Germanic tribe far more barbarous than then either the Ostrogoths or Franks, and the exhausted Byzantines were powerless to protect it. The Lombards made Pavia their capital, and the Lombard Kingdom of Northern Italy lasted for over 200 years until it was conquered by Charlemagne."