St Maurice as a Knight on a Reliquary, Lögum Monastery, Denmark, c.1300

St. Maurice
In the abbey church at Løgumkloster, Denmark
The saint wears a tunic over knee-length chain-mail armor, suggesting that the image is older than the replacement of mail by plate armor in the course of the 16th century. The hat, uncommon in other images of St. Maurice, may be another indication of date. Many medieval portraits have brimless hats that rise directly from the forehead, but these were out of fashion by the beginning of the 17th century.
The heraldic device on the shield appears in other portraits of the saint: a yellow or white cross on a red field. Instead of the usual banner on a staff, in this portrait he carries a spear.

Source: christianiconography

Referenced on p36 Medieval Scandinavian Armies (1): 1100-1300 by David Lindholm and Angus McBride
'St. Maurice', from a painted wooden panel of a reliquary in the Monastery at Lögum, Denmark, painted c.1300; it clearly shows the warrior-saint wearing a coat-of-plates.
A Scandinavian knight in Armies of Feudal Europe 1066-1300 by Ian Heath, based on St Maurice as a Knight on a Reliquary, Lögum Monastery, Denmark

Other illustations of coat of plates:
Arroyo Beatus, Commentary on the Apocalypse by Beatus of Liébana, Spain, c.1220.
First Crusade, Apocalypse by Alexander of Bremen, Cologne or Lower Saxony, Germany, 1249-1250AD. Cambridge University Library, MS Mm.5.31.
Sleeping Guard from a Reliquary at Wienhausen Monastery, Germany, c.1270AD.
Effigy on a Knight's Tomb in Pershore Abbey, Worcestershire, England, c.1280AD.
Effigy of Nils Jonsson, St Mary's Church, Sigtuna, Uppland, Sweden, 1316AD.
Swedish Knights on wall paintings from the Church at Södra Råda in Sweden, 1323AD

See also Knights in 'The Story of St Mary of Antioch', Ål Church, Norway, mid 13th century
'Massacre of the Innocents', Dädesjö Church ceiling paintings, Småland, Sweden, late 13th century
Other Illustrations of Scandinavian Costume and Soldiers
Other Illustrations of 13th century Costume & Soldiers