Abbey of Saint Bertin

The Abbey of Saint Bertin was a Benedictine monastic abbey in Saint-Omer, France. The buildings are now in ruins, which are open to the public. It was initially dedicated to Saint Peter but was rededicated to its second abbot, Saint Bertin. The abbey is known for its Latin cartulary (Chartularium Sithiense) whose first part is attributed to Folcwin. The abbey was founded on the banks of the Aa in the 7th century by Bishop Audomar of Thérouanne, who is now better known as Saint Omer.

He sent the monks Bertin, Momelin, and Ebertram from Sithiu (now St-Omer) to proselytize among the pagans in the region. The abbey soon became one of the most influential monasteries in northern Europe and ranked in importance with Elnon (now St-Amand Abbey) and St. Vaast. Its library included the codex of the Leiden Aratea, from which two copies were made. The Annals of St Bertin are an important source of the history of 9th-century France. Already in the 9th century, the abbey had a priory in Poperinge.

A Romanesque church was constructed in the mid-11th century. It was 25 m (82 ft) high with a 48-metre-high (157 ft) tower. It included a large 14th-century semi-circular sanctuary with five side-chapels...