St. George's Abbey was founded in 1096 by the Counts of Altshausen-Veringen. In 1106 the foundation was confirmed by Pope Paschal II. Towards the end of the 12th century a Benedictine nunnery was also established in Isny but this was moved in about 1189 to Rohrdorf. St. George's Abbey was responsible for the foundation of the town of Isny, which was developed as a market at the end of the 12th century and received municipal status as early as 1235. Both abbey and town enjoyed economic success, abruptly terminated by the plague in 1350, which almost wiped the abbey out.