He wrote sermons against John Wycliffe's views on dominion, though he was later condemned by the church as his views on the sacrament were deemed too close to Wycliffe.
He then returned to Ireland, where he preached against the pastoral privileges of the mendicant friars, particularly their role as confessors.
[1] This resulted in the Dominican Bishop of Meath, William Andrew, charging Crumpe with heresy in 1385.
He was brought before the King's Council and condemned by a commission including the Archbishops of York and Canterbury, in May 1392.
Suspended once again, he returned to Ireland, where he recommenced his disputations against the friars.