The Theban Legion (also known as the Martyrs of Agaunum) figures in Christian hagiography as a Roman legion from Egypt—"six thousand six hundred and sixty-six men"—who converted en masse to Christianity and were martyred together in 286, according to the hagiographies of Saint Maurice, the chief among the Legion's saints. Their feast day is held on September 22. The account According to Eucherius of Lyon, c. 443–450, the Legion was the garrison of the city of Thebes in Egypt. The Legion were quartered in the East until the emperor Maximian ordered them to march to Gaul, to assist him against the rebels of Burgundy. The Theban Legion was commanded in its march by Saint Maurice (Mauritius), Candidus, Innocent, and Exuperius, all of whom are venerated as saints. At Saint-Maurice, Switzerland, then called Agaunum, the orders were given—since the Legion had refused to sacrifice to the Emperor—to "decimate" it by putting to death a tenth of its men. This act was repeated twice before the entire legion was put to death. According to a letter written about 450 by Eucherius, Bishop of Lyon, bodies identified as the martyrs of Agaunum were discovered by Theodore (Theodulus), the first historically identified Bishop of Octudurum, who was present at the Council of Aquileia, 381 and died in 391. The basilica he built in their honor attracted the pilgrim trade; its remains can still be seen, part of the abbey begun in the early sixth century on land donated by King Sigismund of Burgundy. The earliest surviving document describing "the holy Martyrs who have made Agaunum illustrious with their blood" is the letter of Eucherius, which describes the succession of witnesses from the martyrdom to his time, a span of about 150 years. The bishop had made the journey to Agaunum himself, and his report of his visit multiplied a thousandfold the standard formula of the martyrologies: We often hear, do we not, a particular locality or city is held in high honour because of one single martyr who died there, and quite rightly, because in each case the saint gave his precious soul to the most high God. How much more should this sacred place, Agaunum, be reverenced, where so many thousands of martyrs have been slain, with the sword, for the sake of Christ. As with many hagiographies, Eucherius' letter to Bishop Salvius reinforced an existing pilgrimage site. Many of the faithful were