Austrasia

Austrasia was a historical region and the northeastern realm within the core of the Frankish State during the Early Middle Ages, centering on the regions between Meuse, Moselle, Middle Rhine and the Main rivers. It included the original Frankish-ruled territories within what had been the northernmost part of Roman Gaul and parts of Roman Germania. It also stretched beyond the old Roman borders on the Rhine into Frankish areas which had never been formally under Roman rule. It came into being as a part of the Frankish Kingdom, founded by the Merovingian king Clovis I (r. 481–511), who expanded Frankish rule further to the southwest, into Gaul, whose northern regions came to be known as Neustria.

These two realms, or sub-kingdoms (Austrasia and Neustria), along with Aquitaine and Burgundy, were subsequently ruled by various rulers from the Merovingian dynasty, followed in the 8th and 9th centuries by their successors from the Carolingian dynasty, whose own powerbase was in Austrasia itself. The two Frankish dynasties did not always have a single ruling monarch over the whole Frankish realm, and already by 561, Austrasia was ruled as a separate kingdom within the Frankish realm by the Merovingian king Sigebert I (561–575). Kings often allowed different family members to rule sub-kingdoms, and these were sometimes in conflict with each other, despite the underlying continuity of the overall Frankish state.

In 843, by the Treaty of Verdun, Austrasia was divided in three parts, with eastern section being assigned to the East Francia, central regions to the Middle Francia, and the most western part to the West Francia. Further divisions affected mostly the central part of Austrasia, ruled since the Treaty of Prüm (855) by king Lothair II, whose name gave rise to Lotharingia, that corresponded to central Austrasia. It was divided by the Treaty of Meerssen (870), but reunited by the Treaty of Ribemont (880), under the east Frankish rule. During the 9th century, Austrasia was still considered as one of the main regions (stem lands) within the Carolingian Empire, surrounded by Alamannia (to the south), Bavaria (to the south-east), Thuringia (to the north-east), and Saxony (to the north), as attested by the Royal Frankish Annals, and the Annals of Saint Bertin, that mentions not only Austrasia, but also Autrasians.

In time, central Austrasia was more frequently designated as Lotharingia, that became the prevailing term for those regions, while eastern parts of Austrasia came to be known as Franconia.