Christian Saints

        St. Maurice came from Christian Egypt and joined the Roman army. At the head of Theban Legion he fought in the Alps. He refused to pray and sacrifice to Roman gods and together with his companions was massacred on the order of Emperor Maximian. The site of the massacre (now St. Maurice en Valais in Switzerland) became a holy place of pilgrimage at early date. From there the cult spread all over the Alps, then came to Germany and Italy. Like St. George, St. Maurice is  patron of knights and soldiers. From the 12th century, due to linguistic similarity between his name and maurus, he was depicted as a Moor. Thus he became the black saint. Both patrons of soldiers, St. George and St. Maurice, are depicted armed, but St. George is white and on horseback, St. Maurice is often black and almost always a foot soldier.
See: Hans Baldung The Three Kings Altarpiece.
El Greco The Martyrdom of St. Maurice.The Martyrdom of St. Maurice.
Grünewald The Meeting of St. Erasmus and St. Maurice.
Jean Hey, Master of Moulin. Portrait of Francis de Chateaubriand Presented by St. Maurice.
Pontormo. Martyrdom of St. Maurice and the Theban Legions.

Recommended reading:
The Book of Saints: The Lives of the Saints According to the Liturgical Calendar by George Angelini, Victor Hoagland (Editor). Regina Press, Malhame & Company, 1986.
365 Saints: Your Daily Guide to the Wisdom and Wonder of Their Lives by Woodeene Koenig-Brick (Author). Harper SanFrancisco, 1995.
Lives of the Saints: From Mary and Francis of Assisi to John XXIII and Mother Teresa by Richard McBrien (Author). Harper San Francisco, 2001.
All Saints: Daily Reflections on Saints, Prophets, and Witnesses for Our Time by Robert Ellsberg. Crossroad/Herder & Herder, 1997.