Saarpfalz-Kreis in the context of "Circle of the Rhine"

The Circle of the Rhine or Rhine Circle (German: Rheinkreis), sometimes the Bavarian Rheinkreis (Bayerischer Rheinkreis or Baierischer Rheinkreis), was the name given to the territory on the west bank of the Rhine from 1816 to 1837 which was one of 15 (later 8) administrative districts of the Kingdom of Bavaria. Before the French revolutionary wars (1792) most of the land had belonged to the Electoral Palatinate. At the Congress of Vienna in 1815 it was initially promised to the Austrian Empire after having been under a provisional joint Austro-Bavarian administration since 1814. However, in the Treaty of Munich (1816), Austria relinquished the territory to Bavaria.

In 1837, the Circle of the Rhine was renamed the Palatinate (Pfalz). It was also referred to as the Rhenish Palatinate (Rheinpfalz). The territory remained Bavarian until 30 August 1946, with the exception of the area detached in 1920, which roughly corresponded to the present day Saarpfalz-Kreis. It then became part of the newly formed federal state of Rhineland-Palatinate.