Bishop of Ypres and Founder of Jansenism. He was born Cornelius Janssens at Acquoy, in present-day Gelderland, the Netherlands to humble Catholic parents. In 1602 he enrolled at the Old University of Leuven in Belgium, which at that time was in an ideological conflict between the Jesuits, or scholastic party, and the followers of Michael Baius (or Michel De Bay), who aligned himself with Saint Augustine. He sided with Baius and struck up a friendship with a like-minded fellow student, Jen du Vergier de Hauranne. After he received his degree, he went to Paris, France to further study Greek and improve his health, eventually joining du Vergier at his home near Bayonne, France, where he taught for a few years at the bishop's college there. He studied the early Fathers with du Vergier and made plans for a reform of the Church. In 1616 he returned to Leuven to run the College of Saint Pulchseria, a hostel for Dutch students of theology, taking an active part in the university's resistance to the Jesuits as they had established a theological school of their own in Leuven. In hopes of suppressing their encroachments, he travelled to Madrid, Spain in 1624 and again in 1626, the second time narrowly escaped the Inquisition. He supported Philippus Rovenius, the Catholic missionary archbishop of the Northern Netherlands in his opposition to the Jesuits, who were attempting to evangelize the country without regard to the archbishop's wishes. His dislike for the Jesuits did not bring him closer to Protestantism and he yearned to beat them at their own game by showing then that Roman Catholics could interpret the Bible as efficiently as they did. In 1630 he became regius professor of scriptural interpretation at Leuven and worked on his "Augustinus," a large treatise on the theology of Saint Augustine. He made it known that he desired for Belgium to become an independent Catholic republic and be free from Spanish rule, which came to the attention of the Spanish rulers. To reverse their anger he wrote a fiery article in 1635, called the "Mars Gallicus," attacking French ambitions in general and specifically on Cardinal Richelieu's indifference to international Catholic interests. In 1636 he was appointed bishop of Ypres, in Flanders (present-day Belgium) by the Pope Urban VIII and the Spanish Court. In 1638 he became suddenly ill and died in Ypres at the age of 52. His "Augustinus" was published posthumously in 1640. Afterward, a small group of theological doctors extracted eight propositions of his book, later reduced to five. They accused him of misinterpreting Saint Augustine, conflating Jansenists with Lutherans, leading Pope Innocent X in 1643 to condemn the five propositions and again ten years later. The Jesuits then persuaded the Pope to force all Jansenists to sign a formulary to confess their errors. The Jansenists of Port-Royal did sign the formulary; however, some of the Jansenists adopted a radical strategy, alleging that condemning Jansen was equivalent to condemning the Father of the Church, St. Augustine himself, and adamantly refused to sign the formulary. This led to the further radicalization of the King and of the Jesuits, and in 1661 the Jansenist Convent of Port-Royal was closed and the Jansenist community dissolved and it would be ultimately razed in 1710 on orders of French King Louis XIV. In 1713 the Catholic Church finally ended their toleration of the Jansenists' doctrine and Pope Clement IX condemned 101 propositions from "Augustinus" as being heretical.