Knud (Canute) Lavard was the son of King Eric I 'Evergood' of Denmark. Raised partly at the Saxon court of Lothair of Supplinburg, he became Duke of Schleswig in 1115 and was the energetic Christianizer of the still-pagan Wends across the southern Baltic frontier, founding churches and bringing German monastic missionaries to the coast.
His success in pacifying the frontier and his recognition by Emperor Lothair as 'King of the Obotrites' provoked the jealousy of his cousin Magnus the Strong, son of King Niels. On January 7, 1131 — Epiphany — Magnus lured Knud into the forest of Haraldsted near Ringsted on pretext of a meeting and murdered him.
His murder triggered a long Danish civil war in which his son, the future Valdemar I 'the Great', emerged victorious. In 1170 Pope Alexander III canonized Knud Lavard at Ringsted; the same ceremony saw the crowning of Valdemar I's young son Knud VI — uniting royal sainthood and royal succession in a single liturgy. The shrine at St. Bendt's, Ringsted, became the dynastic burial church of the Valdemar kings.