SION [Ger. Sitten], the capital of the Swiss canton of the Valais. It is on the railway between St Maurice ( 25½ m. distant) and Brieg (33 m. distant). Sion is one of the most picturesque little cities in Switzerland, being built around two prominent hillocks that rise from the level valley of the Rhone. The north hillock is crowned by the castle of Tourbillon (built 1294, burnt 1788), which was long the residence of the bishops. The south hillock bears the castle of Valeria, long the residence of the canons (it now contains an historical museum) with the interesting 13th century church of St Catherine. In the town below is the 15th century cathedral, and the Majoria castle (burnt in 1788) the former residence of the " major " (or mayor of the city). There are various other curious objects in the city, which is built on the banks of the Sionne torrent, and is at a height of 1680 ft. above the sea-level. In 1900 Sion contained 6048 inhabitants (mainly Romanists), of whom 1481 were German-speaking and 4446 French-speaking.
Sion [Sedum] dates from Roman times, and the bishop's see was removed thither from Martigny [Ododurum] about 580. In 999 the bishop received from Rudolf III., king of Burgundy, the dignity of count of the Valais, and henceforward was the temporal as well as the spiritual lord of the Valais, retaining this position, at least in part, till 1798.
See also J. Gremaud, Introduction to vol. v. (Lausanne, 1884) of his Documents relatifs à l’histoire du Vallais; R. R. Hoppeler, Beiträge zur Geschichte des Wallis im Mittelalter (Zurich, 1897); B. Rameau, Le Valais historique (Sion, 1886). (W. A. B. C.)