If Cologne remained true to the Catholic cause the merit is principally due to the provincial of the Carmelites. As the leader of the lower clergy he protested against the heretical tendencies of Archbishop Hermann von Wied, who since 1536 had favoured the Reformers.
Von Wied was excommunicated in 1546, gave up the archbishopric in 1547, and died in 1552. It was Billick's exposure of the archbishop's breach of faith that led to the latter's deposition.