Benedictine monks established the settlement on an island in the Po in AD 984. The monastery was renowned for its illuminated manuscripts and choral scores and the despot of the Po plain, Countess Matilda of Canossa, chose to be buried there. The town grew up on the south bank of the river. It has a huge austere L-shaped basilica, dedicated to San Benedetto (St Benedict). Stucco work and frescos (some by Guido Reni) embellish the chapels. The choir-stall wood-carvings and 12thC floor mosaics in the Immacolata chapel are very precious.