Trier was one of the three Regierungsbezirke of Rhineland-Palatinate, Germany, located in the west of the state.The region was created in 1815 as part of the Prussian Rhineland. Until 1920 the bulk of what then became the Territory of Saar Basin was part of the Trier Region. Only the east of the Saar Territory, today's Saar-Palatinate district, formerly the western fringes of the then Bavarian Rhenish Palatinate, was previously no part of the Trier Region.