 They are first mentioned by Roman sources in the third century.In the 4th century, they were among the peoples incorporated into the Hunnic Empire, within which they formed one of the most important parts.After the death of Attila, the Gepids under their leader Ardaric, led an alliance of other peoples who had been in the empire, and defeated the sons of Attila and their remaining allies at the Battle of Nedao in 454.