May 24, 1089 (traditional date): Archbishop of Canterbury, scholar, and church reformer Lanfranc dies. Known primarily for his development of the doctrine of transubstantiation, in which the eucharistic bread and wine become Christ's body and blood, he also educated brilliant scholar Anselm and future pope Alexander II.

May 24, 1543: Polish astronomer and cleric Nicolas Copernicus dies in Poland. His heliocentric (sun-centered) concept of the solar system was radical, though not unheard of before ...