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
Priory of Sion 1889 and 1895, which is problematic considering that de Sède's book was trying to make a case that these documents were centuries old. In 1969, English actor and science-fiction scriptwriter Henry Lincoln became intrigued after reading "Le Trésor Maudit". He discovered one of the encrypted messages, which read ""À Dagobert II Roi et à Sion est ce trésor, et il est là mort"" ("To Dagobert II, King, and to Sion belongs this treasure and he is there dead"). This was possibly an allusion to the tomb and shrine of Sigebert IV, a real or mythical son of Dagobert II which