Brunhilda was queen consort of Austrasia, part of Francia, by marriage to the Merovingian king Sigebert I of Austrasia, and regent for her son, grandson and great-grandson.

Austrasia was a territory which formed the north-eastern section of the Kingdom of the Franks from the 6th to 8th centuries, ruled by the Frankish Merovingian and Carolingian dynasties during the Early Middle Ages. It was centred on the Meuse, Middle Rhine, and the Moselle rivers, and was the original territory of the Franks, including both the so-called Salian Franks and Ripuarian Franks, which Clovis I, King of the Franks (481–511) conquered after first taking control of the bordering part of Roman Gaul, which is sometimes described in this period as Neustria.