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
Lauda Sion Lauda Sion "Lauda Sion Salvatorem" is a sequence prescribed for the Roman Catholic Mass for the feast of Corpus Christi. It was written by St. Thomas Aquinas around 1264, at the request of Pope Urban IV for the new Mass of this feast, along with "Pange lingua", "Sacris solemniis", "Adoro te devote", and "Verbum supernum prodiens", which are used in the Divine Office. The Gregorian melody of the "Lauda Sion" is borrowed from the eleventh-century sequence "Laetabundi iubilemus" attributed to Adam of Saint Victor. The hymn tells of the institution of the Eucharist and clearly expresses the belief of the