Several groups revolted against Agila, as listed…
551 CE
Several groups revolted against Agila, as listed by historian Peter Heather: a local dynast, Aspidius, established a hegemony in one mountainous region; the landowners of Cantabria established a "senate" to govern their affairs; there are also the Sappi and Suani mentioned by John of Biclar.
The most important rebel opposed to Agila is Athanagild, whose open revolt begins in 551, following Agila's defeat at Cordoba.
Athanagild takes Seville, capital of Baetica, and presumes to rule as king in opposition to Agila.
Exactly who approached the Empire for assistance and when is also disputed; the primary sources are divided.
Even the name of the general of the imperial army is disputed.
The armies of Agila and Athanagild meet at Seville, where Agila meets a second defeat.
At this point, a third party enters the war between these two: the Empire.
As Peter Heather writes, "One of the two—which is the subject of varying report—summoned a Byzantine army, which duly arrived in southern Spain in 552."
Heather understands Isidore's chronicle states that Athangild summoned the imperial forces in autumn of 551 or winter of 552, while Jordanes implies in his Getica that Agila had asked Justinian for help.