The Franks in the western part of Francia (Neustria and western Austrasia) gradually adopted Gallo-Romance by the beginning of the OHG period, with the linguistic boundary later stabilised approximately along the course of the Meuse and Moselle in the east, and the northern boundary probably a little further south than the current boundary between French and Flemish. North of this line, the Franks retained their language, but it was not affected by the Second Sound Shift, which thus separated their Low Franconian variety (the ancestor of Dutch) from the more easterly Franconian dialects which formed part of Old High German.