The Ostrogoths were a Roman-era Germanic people. In the 5th century, they followed the Visigoths in creating one of the two great Gothic kingdoms within the Western Roman Empire, drawing upon the large Gothic populations who had settled in the Balkans in the 4th century. While the Visigoths had formed under the leadership of Alaric I, the new Ostrogothic political entity which came to rule Italy was formed in the Balkans under Theodoric the Great.

The Visigoths were a Germanic people united under the rule of a king and living within the Roman Empire during late antiquity. The Visigoths first appeared in the Balkans, as a Roman-allied barbarian military group united under the command of Alaric I. Their exact origins are believed to have been diverse but they probably included many descendants of the Thervingi who had moved into the Roman Empire beginning in 376 and had played a major role in defeating the Romans at the Battle of Adrianople in 378. Relations between the Romans and Alaric's Visigoths varied, with the two groups making treaties when convenient, and warring with one another when not. Under Alaric, the Visigoths invaded Italy and sacked Rome in August 410.