The Drenther Crusade was a military campaign launched against the inhabitants of Drenthe with the approval of the Papacy in 1228 and lasting until 1232. It was led by Willibrand, Bishop of Utrecht, commanding an army composed mostly of Frisian crusaders. There are two main sources for the conflict, both written around 1232–33 by contemporaries and eyewitnesses in the following of the bishop: the and A Certain Narrative of Groningen, Drenthe and Coevorden.