The most important territory in the area was the Electorate of Palatinate.
The Electoral Palatinate (short for Electorate Palatinate, more precisely Electoral Palatinate by the Rhine or Electoral Rhenish Palatinate) was an electorate of the Holy Roman Empire that existed until 1803.
That mean the correct name was: kurfürstliche Pfalzgrafschaft bei Rhein.
The Electoral Palatinate was located on the Upper and Middle Rhine, between the Moselle and Kraichgau, with its core area on the lower Neckar and its capitals in Heidelberg and Mannheim. The Electoral Palatinate territory was not contiguous, but a "patchwork quilt" of exclaves and enclaves typical of the time; individual territories were even shared with other states. At the end of its existence, the territory covered 8200 square kilometers.
Former Electoral Palatinate territories are now located in the German states of Baden-Württemberg, Rhineland-Palatinate, Hesse, Bavaria (Upper Palatinate = Upper Palatinate, Palatinate-Neuburg), Saarland, as well as in the departments of Bas-Rhin (Lower Alsace) and Moselle, which today belong to France.
This means that you would have to know a little more exactly where your ancestors came from, then I might be able to determine exactly which area it is.