She was married in 515 to Eutharic, an Ostrogoth of the old Areal line, who had previously been living in Spain. Her husband died, apparently in the early years of her marriage, leaving her with two children, Athalaric and Matasuentha. On the death of her father in 526, her son succeeded him, but she held the power as regent for her son. Deeply imbued with the old Roman culture, she gave to that son's education a more refined and literary turn than suited the ideas of her Gothic subjects. Conscious of her unpopularity she banished, and afterwards put to death, three Gothic nobles whom she suspected of intriguing against her rule, and at the same time opened negotiations with the emperor Justinian I with the view of removing herself and the Gothic treasure to Constantinople. Her son's death in 534 made little change in the posture of affairs.
Now queen, Amalasuntha made her cousin Theodahad partner of her throne (not, as sometimes stated, her husband, for his wife was still living), with the intent of strengthening her position. The choice was unfortunate, for Theodahad, in spite of a varnish of literary culture, was a coward and a scoundrel. He fostered the disaffection of the Goths, and either by his orders or with his permission, Amalasuntha was imprisoned on an island in the Tuscan lake of Bolsena, where in the spring of 535 she was murdered in her bath.
The letters of Cassiodorus, chief minister and literary adviser of Amalasuntha, and the histories of Procopius and Jordanes, give us our chief information as to the character of Amalasuntha.