On a hill overlooking the vast Lavant valley stood, at the end of the 11th century, the castle of Lavant, with a small church dedicated to St Giles. Count Engelbert of Sponheim, carrying out the wishes of his mother, Countess Riccarda, who had already built a church dedicated to St Paul there, summoned in 1091 a group of Benedictine monks from Hirsau to found a new abbey; the church was dedicated in 1093. The present Romanesque basilica is of the Hirsau architectural type, a rare example that escaped the usual subsequent stylistic transformations; after the fire of 1347 the vaults were rebuilt and it was rededicated in 1375: it has three naves with a transept, three apses and a crypt (walled up for centuries). The later Gothic vaults were frescoed by the masters M. and F. Pacher (1470-80). The furnishings, while largely modern, are mostly Baroque. Recently, beneath layers of whitewash, valuable frescoes from the 13th-15th centuries were discovered. Around the church, still on the hill, are grouped the monastic buildings, partly medieval but remodelled in the Baroque period. Emperor Joseph II suppressed the monastery in 1782.
When, in 1805, the famous abbey of Sankt Blasien in the Black Forest was also suppressed, Emperor Francis I offered Sankt Paul as a new seat. In 1809, Abbot Beda Rotter and the monks, together with almost all the cultural and artistic treasures of Sankt Blasien, transferred there. At Sankt Paul a gymnasium was established in 1810, with a boarding school and unrivalled collections of books, manuscripts (a codex of works by St Ambrose, 5th century; the Reichenau Sacramentary, 10th century), archival treasures, many unpublished works by the monks of Sankt Blasien, and precious sacred and profane relics.