When Sigebert I of Austrasia died in 575, Chilperic sent Desiderius to invade his kingdom, but Guntram of Burgundy sent the patrician Mummolus against him and Desiderius was defeated and forced to retreat, leaving Austrasia to Sigebert's son Childebert II.
Paul records that it was around this time, when Sigebert I of Austrasia was assassinated by Chilperic I of Neustria (584), that Euin married a daughter of Garibald I, whom Paul refers to as "king of the Bavarians".
But at Sigebert's moment of triumph, when he had just been declared king by Chilperic's subjects at Vitry-en-Artois, he was struck down by two assassins working for Fredegund.