Eldest son of a shoemaker, John was born at Diest, Brabant. He early wanted to be a priest, and when thirteen became a servant in the household of one of the Cathedral canons at Malines, John Froymont. In 1615, he entered the newly founded Jesuit College at Malines, and the following year became a Jesuit novice. He was sent to Rome in 1618 to continue his studies, and was known for his diligence and piety, impressing all with his holiness and stress on perfection in little things. He died there on August 13. Many miracles were attributed to him after his death, and he was canonized in 1888. He is the patron of altar boys.