Duchy of Jülich
In German sources, the dialects linguistically counting as Limburgish spoken to the east of the river Rhine are called "Bergish" (named after the former Duchy of Berg). Not only West of the river Rhine (the former Duchy of Jülich) they are called "Low Rhenish", which is considered a transitional zone between Low Franconian and Ripuarian. Thus, formerly German linguists tended to call these dialects Low German.