Jansenism was a Christian theological movement, primarily in France, that emphasized original sin, human depravity, the necessity of divine grace, and predestination. The movement originated from the posthumously published work of the Dutch theologian Cornelius Jansen, who died in 1638. It was first popularized by Jansen's friend Jean du Vergier, Abbé de Saint-Cyran, and after du Vergier's death in 1643, was led by Antoine Arnauld. Through the 17th and into the 18th centuries, Jansenism was a distinct movement within the Catholic Church. The theological centre of the movement was the Parisian convent of Port-Royal, which was a haven for writers including du Vergier, Arnauld, Pierre Nicole, Blaise Pascal, and Jean Racine.
Jansenism was opposed by many in the Catholic hierarchy, especially the Jesuits. Although the Jansenists identified themselves only as rigorous followers of Augustine of Hippo's teachings, Jesuits coined the term "Jansenism" to identify them as having Calvinist affinities. The papal bull Cum occasione, issued by Pope Innocent X in 1653, condemned five cardinal doctrines of Jansenism as heresy—especially the relationship between human free will and efficacious grace, wherein the teachings of Augustine, as presented by the Jansenists, contradicted the teachings of the Jesuit School. Jansenist leaders endeavored to accommodate the pope's pronouncements while retaining their uniqueness, and enjoyed a measure of peace in the late 17th century under Pope Clement IX. However, further controversy led to the bull Unigenitus, issued by Clement XI in 1713, which marked the end of Catholic toleration of Jansenist doctrine.