sentences:  He was involved in the Pfefferkorn controversy, and was one of the four imperial commissioners appointed to examine Jewish books for blasphemy against Christianity, the others being Johannes Pfefferkorn, Johann Reuchlin, and Jacob van Hochstraten.His work, "Judenbüchlein", published in Cologne in 1508 or 1509 described the conditions and customs of Jews with a view toward aiding in their conversion.He disputed with learned Jews before the Archbishop of Cologne at Bonn, and secured the expulsion of Jews from Brühl, Deutz, and other towns in the Diocese of Cologne.