The Abbey of Saint Gall (German: Fürstabtei St. Gallen) is a Roman Catholic religious complex in the city of St. Gallen in present-day Switzerland. The Carolingian-era Abbey has existed since 719 and became an independent principality during the 13th century, and was for many centuries one of the chief Benedictine abbeys in Europe. It was founded by Saint Othmar on the spot where Saint Gall had erected his hermitage. The library at the Abbey is one of the richest medieval libraries in the world. Since 1983 it has been a UNESCO World Heritage Site.