Reinhardsbrunn in Friedrichroda near Gotha, in the German state of Thuringia, is the site of a formerly prominent Bendictine abbey, the house monastery of the Ludovingian Landgraves of Thuringia abbey extant between 1085 and 1525. Later used as an administrative seat by the Ernestine dukes of Saxony, the premises were turned into a castle and park erected by the Dukes of Saxe-Coburg and Gotha from 1827.
Reinhardsbrunn Abbey (German: Kloster Reinhardsbrunn) was a house of the Benedictine Order founded by the Thuringian landgrave Louis the Springer in 1085, against the background of the fierce Investiture Controversy between Emperor and Pope. It was settled by monks descending from Hirsau Abbey and soon evolved as a centre of the Hirsau Reforms in Thuringia. Like Hirsau, the Reinhardsbrunn monastery was closely related to Cluny Abbey; it stood under Papal protection from 1093. It was also of significance as the proprietary monastery and burial ground of the Ludovingian landgraves like Hermann I who was entombed here in 1217.
The monastery became less important after the extinction of the Ludovingians in 1247. Nevertheless, their Wettin successors still used it as a dynastic burial site and an important chronicle was commissioned around 1340, reflecting the history of Thuringia and Germany back to the 6th century. The monastery was looted and sacked during the German Peasants' War in 1525. The monks took refuge within the walls of Gotha and the site was secularized and sold to the Electors of Saxony. While the surrounding estates were administrated by a Saxon Amtmann officials, the former monastery buildings fell into ruin.