Theudahad, Theoderich's nephew, who had inherited great estates in Tuscany – the district lying on the coast northward from Rome. Now, Amalasontha had recently summoned Theudahad to Ravenna and reproached him for his unjust seizure of the lands of Roman citizens, his neighbours, as also of lands belonging to the Crown; and had obliged him to make restoration and apology.
The envoy and the bishops returned, with the welcome news that Theudahad, in return for a settled income and an estate at Constantinople, was willing, for hatred of Amalasontha, to betray Tuscany to Justinian's soldiers whenever he cared to send an army of occupation; and that Amalasontha was secredy willing to transfer her regency of Italy to Justinian on the same terms – since she could not long continue to control her son. But her official reply in the matter of Lilybacum was a denial that Justinian had any right to it.
Then a sudden event changed the whole complexion of events. Young Athalrich, his health undermined by drink and debauchery, fell into a decline and died. Amalasontha, who only ruled by virtue of being his mother, was thus, according to Gothic law, relegated to private citizenship. She decided to choose at once a noble Goth, by marriage to whom she could still remain queen. There was, she thought, no more suitable person to become her husband than this same Theudahad, her cousin (of whose intrigues with Justinian she was unaware, as he of hers): an elderly, unsoldierly man, unlike any other of the Goths in having taken to the study of philosophy and to the writing of Latin hexameter verse. He would no doubt feel honoured by a union with herself, and would allow her to rule in his name without interference. She therefore proposed marriage to him, emphasizing the advantage of thus protecting himself against the hostility both of the Gothic nobility, who despised him for his learning, and of the Italians, who hated him for his rapacity. Nobody had a better claim to the throne than he, she said, but without her he could not hope cither to seize or hold it. He consented, with every appearance of pleasure, and was duly crowned king, and acclaimed as such by the Goths; for no other claimant of royal blood appeared. But Amalasontha had over-reached herself. What should Theudahad do, as soon as he had the crown on his head, but violate his sacred oath to her that he would not meddle in public business. He actually excluded her from his council room and carried her off to a small island of his in a Tuscan lake, keeping her a close prisoner there.
When Justinian heard of Theudahad's action, lie was more pleased than he pretended to be. He sent another envoy to Italy, to inform Amalasontha that she would be given all the support against her enemies that she needed; and the envoy had instructions not to conceal this message from Theudahad or from any of his nobles. He hoped thus to throw the whole kingdom into confusion. But by the time that the envoy arrived in Italy, Amalasontha was dead: the relatives of the three young men whom she had killed had persuaded Theudahad to avenge their death. She was surprised one summer afternoon as she was bathing with her women in the lake, and her head forced under the water until she drowned.
Now, though Justinian continued to protest his great love for Theodora, she also was relieved at this queen's death, whom she regarded as a rival. It was true that Amalasontha, whom Justinian had known when she was a child, was of better birth than Theodora and a little younger and far more beautiful. Cappadocian John put it about that Theodora had arranged the assassination herself.
Here then was Justinian's pretext for a war – the murder of an innocent woman, his ally. Tic found an augury of success in the unpopularity and inefficacy of King Theudahad, whose verses did not even scan, it was said, and whose philosophical capacity was nothing. But Theudahad heard and believed a rumour, arising out of Theodora's jealousy of Amalasontha, that the perfidious Justinian had indeed intended to invade Italy with his army and marry Amalasontha, having first divorced Theodora; further, that he had planned to persecute the Goths as heretics. He offered this story to his Court as an excuse for the murder of his wife. They approved of his actions; for it was now clear at least that Amalasontha had been carrying on a treasonable correspondence with Justinian. But Theudahad officially assured Justinian's envoy that the murder had been committed without his knowledge and against his wishes.