From the old Dominican Martyrology for the 22nd of September:
At Sitten in Gaul, at Saint-Maurice, the holy Theban martyrs Maurice, Exuperius, Candidus, Victor, Innocent, and Vitalis, with their companions of the same Legion. In the reign of Maximian, they were slain for Christ, thus enlightening the world by their martyrdom.
The Theban Legion! To-day, Holy Church keeps the memory (at least in the traditional Dominican Rite) of those intrepid soldiers who died for their true champion, Christ the King of Martyrs, rather than obey impious and inhuman commands. In late days of pagan Rome, at Agaunum (now Saint-Maurice-en-Valais in Switzerland), many Christian soldiers were put to death; in due time their cultus was solemnized in that place, as attested by a letter of one Eucherius, bishop of Lyon (c. 434–450), who explains therein that it was only in the episcopate of Theodore of Octodurum (369-391), a long time after the occurrence, that a basilica there was built in veneration of these intrepid milites Christi. The paucity of the evidence, and the difficulties involved in the claim that the whole Legion was Christian, subjected to two decimations and then wholesale massacre, has given some pause; but, as with other examples of the cultus of early martyrs, it may be affirmed that certainly some men, those six whose names have come down to us, suffered death on account of the Holy Faith, and these men's courage and witness to the Truth deserve eternal memory. May these saints of long ago pray for us sinners now shuffling along this mortal coil, that when our turn has passed and the world has forgotten us, we may be ever precious in the sight and knowledge of God.
Their Collect - remembering that for the saints, their natal day is their day of death, or rather of birth into immortal glory, passing from this world to the Father:
Annue, quaesumus, omnipotens Deus: ut sanctorum Martyrum tuorum Mauritii, Exsuperii, Candidi, Vitalis, Innocentii ac Sociorum eorumdem nos laetificet festiva solemnitas, ut, quorum suffragiis nitimur, eorum natalitiis gloriemur. Per...
(We beseech, almighty God: that as this annual festive solemnity of Thy holy Martyrs Maurice, Exsuperius, Candidus, Vitalis, Innocent and their Companions may rejoice us, so we, enlightened by their suffrages, may glory in their natal day. Through...)
(The Neo-Gallican Paris Missal of 1738 also included this collect, only slightly modified by omitting the names of St Maurice's companions.)
As an interesting sidelight, the Abbey later founded at Agaunum by St Sigismund, first Catholic king of the Burgundians, and himself martyred by his godless relatives, has a special claim to fame: for, as St Avitus remarked in his still-extant sermon preached at its opening, the monastery would be devoted to such assiduous psalmody (the modern term is laus perennis) that the chanting of the psalms would never cease – it is thought that, as well as all the monks singing the canonical Hours together, they were divided into groups, each of which took responsibility for maintaining the praise of God in choir in between one pair of Hours.
In later years, St Maurice (after whom St Moritz and other spots were later named) came to be special patron of the Holy Roman Emperors, and relics of his military equipage became part of the imperial regalia - his relics were translated to Magdeburg about a thousand years ago.