Roman Catholic Diocese of Sion Roman Catholic Diocese of Sion The Diocese of Sion (, , ) is a Roman Catholic ecclesiastical territory in the canton of Valais, Switzerland. It is the oldest bishopric in the country and one of the oldest north of the Alps. The history of the Bishops of Sion, of the Abbey of St. Maurice of Valais as a whole are inextricably intertwined. The see was established at Octodurum, now called Martigny, the capital of the Roman province of Alpes Poeninae. The first authentically historical bishop was Saint Theodore/Theodolus (died in 391), who was present at the Council of Aquileia in
Sion, Switzerland the "Bibliothèque municipale de Sion", the "HES-SO Valais Médiathèque santé-social" and the "HES-SO Valais, Domaine Sciences de l'ingénieur". There was a combined total () of 690,513 books or other media in the libraries, and in the same year a total of 294,320 items were loaned out. Sion has two high schools (colleges) Sion is also host to the : The HES-SO Valais offers education in Sciences, Engineering, Economics, Information Technology and Health Sciences. Sion is situated on the main railway line and the motorway, and also has an airport (Sion Airport). From the , 21,220 or 78.1% were Roman Catholic,