Audomar (Latin Audomarus, French Omer) was — per the early-medieval Vita — a young Aquitanian Catholic noble who entered religious life in his late teens at the great Irish-Frankish monastic foundation of Luxeuil under the abbot Eustace (a personal disciple of Columbanus; see Columbanus's entry already in the catalogue).
Audomar spent some twenty-five years as a Luxeuil monk before being elevated, around 637 AD, to the Frankish episcopal see of Thérouanne (in the Pas-de-Calais region of northern France, then a substantially still-pagan territory of the Belgic-Flemish frontier). He governed the Thérouanne see for some 33 years through extensive substantial missionary expansion across the Pas-de-Calais and Flemish territories.
The substantial small town that grew up around the small monastic foundation he established at Sithiu (near the modern small Pas-de-Calais town that bears his name, Saint-Omer) became the continuous Catholic centre of the Pas-de-Calais region. The Abbey of Saint-Bertin at Saint-Omer (the great medieval Pas-de-Calais Catholic monastic foundation) was founded by his disciple Bertin under his direct supervision in the 640s.
Audomar died — substantially elderly — on September 9, 670, at the small village of Wavrans-sur-l'Aa near Saint-Omer. The medieval Catholic-Flemish English-Jesuit centre of Saint-Omer in the early-modern period (the continuous English Jesuit Catholic-educational foundation outside England during the long English Catholic-recusant period) preserved his name as one of the continuous English-Catholic-educational identifications — Stonyhurst College in Lancashire, the great English Jesuit school, traces its continuity through the Catholic-recusant centuries to the Saint-Omer foundation.