St. Eucherius, bishop of Lyons (434–450), tells of the decimation of a legion of Christian soldiers, recruited at Thebes in Egypt, which took place because they refused to shed innocent Christian blood in a campaign waged near Lake Geneva in Switzerland. Other accounts say that the soldiers died because they refused to offer sacrifice. Whether the legion referred to is the tertia Diocletiana Thebaeorum or the prima Maximiana Thebaeorum is not known. A church built at Agaunum (St. Maurice-en-Valais) in the 4th century by Theodore, bishop of Octodurum (Martigny), established the fact of the martyrdom of St. Maurice, the primicerius of the legion, and his companions. As to how many troops actually perished, we have no certain knowledge. Eucherius himself added the names of Urso and Victor of Solothurn to the list of martyrs. In the 6th century Gregory of Tours claimed that 50 martyrs of Cologne were in the ranks of the Theban Legion. Because Agaunum was a popular pilgrimage spot, many places in western Europe boasted a representative among the Theban legionaries. Devotion to the legion was particularly strong in the region of the Rhine during the Middle Ages.
Bibliography: h. leclercq, Dictionnaire d'archéologie chrétienne et de liturgie, ed. f. cabrol, h. leclercq and h. i. marrou, 15 v. (Paris 1907–53) 10.2:2699–2729. a. butler, The Lives of the Saints, ed. h. thurston and d. attwater, 4 v. (New York 1956) 3:619–621.