- See Sigeberht II of Essex for the Saxon ruler by that name
Sigebert II (601–613) was king of Burgundy and Austrasia (613). Bastard son of Theuderic II, he succeeded his father in 613; but the mayor of the palace of Austrasia, Warnachar, feared that at his young age he would fall under the influence of his great-grandmother Brunhilda. Brunhilda had brought him before a national assembly, where he was proclaimed by the nobles, who did homage to him over both his father's kingdoms. But Warnachar and Rado, mayor of the palace of Burgundy, abandoned the cause of Brunhilda and the young king and joined with Clotaire II of Neustria, promising not to rise in defence of the queen-regent and recognising Clotaire as rightful regent and guardian of Sigebert. Brunhilda and Sigebert met Clotaire's army on the Aisne, but the Patrician Aletheus, Duke Rocco, and Duke Sigvald deserted the host and the grand old woman and her king had to flee. They got as far as the Orbe before Clotaire's minions caught up with them by lake Neuchâtel. Both of them and Sigebert's younger brother Corbo were executed by Clotaire's orders. Brunhilda was tortured on the rack for three days before being ripped apart between four horses, thus ending the long and bloody feud between Austrasia and Neustria, and reuniting the two kingdoms. Clotaire then ruled the entire realm of the Franks.