Abstract
Sebald Welser (1557-1589), the Lutheran son of a Nuremberg patrician, visited the Catholic University of Louvain in 1577 for a semester in pursuit of his legal studies. While there, he became caught up in the spectacular Catholic culture of the southern Netherlands and the fast-breaking political events surrounding the collapse of the Spanish occupation. During the year, he kept a diary in which his experiences are recorded, not the least of which were his kissing a monstrance at the annual procession of the Eucharist in Brussels and his buying an indulgence at St. Michael's Church in Louvain. Thanks to the survival of his diary, that seemingly contradictory behavior can be explained and the mental world of a sixteenth-century teenager illuminated.