Saint-Maurice is a city in the Swiss canton of Valais and the capital of the district of Saint-Maurice. On 1 January 2013, the former municipality of Mex merged into the municipality of Saint-Maurice. Saint-Maurice is the site of the Ancient Roman outpost of Agaunum and the 6th-century Abbey of Saint-Maurice d'Agaune. The city is located at the entrance of a pass leading to the upper part of the Rhône valley. As such, it has a strategic importance, and defence work were built from the 15th century to control this access. The Fortress Saint-Maurice was constructed in the surrounding mountainsides from 1880 through 1995. History Saint-Maurice is first mentioned in 200 as Acaun[ensis] [quadragesimae] Gal[liarum]. In respect to Saint Maurice, the name was changed from Acaunum () to Saint-Maurice in 1003. Some traces of a Bronze Age settlement were found at the foot of the rocky spur in town. There was a Roman era town at Saint-Maurice, but very little is known about the actual layout of it. There was a customs post at Acaunum, where an import and export tariff of 2.5% was levied. The town probably had a shrine to water nymphs. According to tradition, Saint Maurice and his southern Egyptian companions of the Theban Legion were martyred in Acaunum during the reign of Maximian (286-310). Around 360-370 Theodul, the first Bishop of Valais, built a basilica in Acaunum in their honor. The basilica became a popular pilgrimage site. In 515, the King of Burgundy Sigismund founded the Abbey, which he endowed with rich land. In 523, the town was invaded by the Franks, followed in 574 by the Lombards and in the mid-10th century, by the Saracens. In 888 Rudolf of Welf was crowned King of Burgundy in the Abbey. In 1034, the entire Chablais region, which included Saint-Maurice, was acquired by the Duchy of Savoy. The towns of Saint-Maurice and Monthey formed a Kastlanei or district. Around 1300, the Kastlan or vogt moved from Monthey to Saint-Maurice. The abbot exercised dominion over the abbey and the town. Citizens of the town were first mentioned in 1170 and by 1275, the citizens elected two mayors. In 1246 Amadeus IV, Count of Savoy enfeoffed Saint-Maurice to King Henry III of England in return for a pension along with the castles at Bard, Avigliana and Susa. In the 13th century the town was surrounded by walls. Count Amadeus V of