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, who expanded Frankish rule further to the southwest, into Gaul, whose northern regions came to be known as Neustria.