The Abbey of Saint-Maurice, a monastery of the Augustinian canons, is considered the oldest monastery in the West that has existed without interruption. In 2014/2015 the abbey celebrated its 1500th anniversary.
The abbey's origins date back to a sanctuary built over the tomb of Saint Maurice and his companions from the Theban Legion, who are said to have suffered martyrdom with him towards the end of the 3rd century AD became. The sanctuary was at the old Roman military base of Agaunum.
foundations of the previous church
Interior of the Abbey Church
The abbey in a model of the town of Saint-Maurice
View of the Abbey Church
Around 380, Saint Theodore, Bishop of Octodurus (Martigny), transferred the relics of the martyrs to the large caves at the foot of the Felsentor, through which the Rhone leaves Valais. As a result, Agaunum developed into a Christian place of pilgrimage. Saint Sigismund, son of the Burgundian king Gundobad, founded the monastery that still exists today on September 22, 515, and Saint Ambrose (516–520), abbot, built a new basilica over the original sanctuary. In the 9th century the monks were replaced by canons and in 1128 they adopted the Rule of Augustine.
In 961, the later Emperor Otto I moved the relics of St. Mauritius, including the important Holy Lance, the oldest piece of the imperial jewels of the kings and emperors of the Holy Roman Empire, to Magdeburg Cathedral. This dealt a severe blow to the abbey's attractiveness to pilgrims.
1148 consecrated Pope Eugene III. the new church.
Source: Wikipedia