Liudger (Liudgerus) was born around 742 at Zuilen near Utrecht, son of the Frisian noble Thiadgrim and Liafburg. His maternal grandmother had as a baby been left to die by her pagan father, but rescued by Christian neighbours — placing Liudger in the first generation of Frisian Christianity that the Anglo-Saxon mission (Willibrord, Boniface) had founded.
He studied at Utrecht under his uncle St. Gregory of Utrecht, then at York under Alcuin (775–778) — placing him directly in the Anglo-Saxon Catholic intellectual tradition that fed Charlemagne's court school. Returning to Frisia, he was ordained priest at Cologne in 777 and assigned to the mission at Deventer (St. Lebuin's station), where he rebuilt the chapel the saint had founded.
The pagan Saxon revolt of 782 under Widukind drove him into a three-year exile at Monte Cassino. Returning under Charlemagne's reconquest of Saxony, Liudger evangelized the Frisian islands (Helgoland, where he destroyed the pagan shrine), the Ems and Lippe valleys, and finally the new diocese of Mimigernaford — the establishment of what became the great city of Münster (literally 'minster', from his monastic see).
In 799 he founded the abbey of Werden on the Ruhr — the Westphalian Benedictine centre — and around 805 was consecrated first Bishop of Münster by Hildebald of Cologne. He died on Sunday March 26, 809, at Billerbeck immediately after celebrating Mass and preaching, and was buried at his foundation of Werden, where his shrine remains in continuous veneration twelve centuries later.