Abbey of St. Martin, Premonstratensian abbey in Laon, France

The Abbey of St. Martin in Laon is a former Premonstratensian monastery whose church was built from the 1130s to the 1160s, with two-level nave, vaulted choir, and a west facade begun around 1270. The south transept facade and the towers at the end of the side aisles date to the late 13th century; the spires above the towers were removed in 1737. The monastic buildings now serve as a municipal museum.

Bishop Barthélemy of Jur installed Norbert of Xanten at a decayed Carolingian college of canons in 1119; after that failed, twelve canons from Prémontré replaced the canons in 1124, founding the abbey. The church was built from the 1130s to the late 13th century. The abbey was dissolved in the French Revolution, and its buildings became a hospital in 1810.

The abbey's church keeps the relic of Saint Lawrence, a left arm stolen from a Premonstratensian monastery in Hungary around 1230 by a canon named Thomas. Bishop Anselme de Mauny received it at Laon and had a reliquary made; from 1243 Bishop Garnier granted indulgences during the octave of Saint Lawrence. The relic drew pilgrims and gave its name to a fair held on 21 December, moved in 1523 to the first Monday of January and lasting six days.

The church is open to visitors while the other buildings operate as a hospital and are not accessible to the public. Check opening hours before visiting since access may be limited at certain times.

The abbey's first abbot, Gautier, brought a fragment of the True Cross back from Byzantium. The community also kept the left arm of Saint Lawrence, stolen from a Hungarian monastery around 1230, which drew pilgrims and a fair held on 21 December, later moved to the first Monday of January.