Montreuil origins are closely linked to religious history. Its name is coming from a latin word ‘monasteriolum’ that means ‘small monastery’.
In 926 AD, monks of the abbey of Landévennec (Brittany) ran away because of Norman invasions and found refuge in Montreuil to found the abbey of Saint-Walloy (strange other local name for Saint-Guénolé). In 1111 AD, that abbey was renamed when Saint-Saulve relics were brought.
In Middle-Ages, pilgrims were attracted by numerous relics and provided a character of sanctity to the town. It was called then the ‘Ponthieu Necropolis’.
In 1467, a natural catastrophe caused the collapse of six religious monuments at least including the Hôtel-Dieu and the Saint-Saulve Church. The last monument was entirely rebuilt in the very beginning of the 16th century. But it was only a short respite: the armies of Charles Quint set the church on fire when the town had been attacked. It was partly rebuilt because of the financial cost.
The whole Sacred Art Treasure disappeared in 1793. Saint-Austreberthe relics including a richly decorated pastoral crosier were placed indoors after the French Revolution. In the 19th century, the addition of other relics makes the whole sacred treasure one of the richest of the North of France.
It is possible to see a part of it during a visit inside the Abbey Church.