Cornelius Otto Jansen

Cornelius Jansen
Bishop of Ypres
Painting of Cornelius Jansen.
Church	Catholic Church
Diocese	Diocese of Ypres
Installed	1635
Term ended	1638
Predecessor	Georges Chamberlain
Successor	Josse Bouckaert
Personal details
Born	28 October 1585 Acquoy, County of Holland, Dutch Republic
Died	6 May 1638 Ypres, Spanish Netherlands
Education	University of Leuven

Corneille Janssens (/ˈdʒænsən/;Dutch: [ˈjɑnsəns]), commonly known by the Latinized name Cornelius Jansen ([ˈjɑnsə(n)]) or Jansenius (28 October 1585 – 6 May 1638), was the Dutch Catholic bishop of Ypres in Flanders and the father of a theological movement known as Jansenism.

He was born of humble Catholic parentage at Acquoy then in the province of Holland, now in Gelderland, the Netherlands. In 1602 he entered the University of Leuven, then in the throes of an ideological conflict between the Jesuit — or scholastic — party and the followers of Michael Baius, who swore by St. Augustine. Jansen ended by attaching himself strongly to the latter "Augustinian" party, and presently made a momentous friendship with a like-minded fellow-student, Jean du Vergier de Hauranne, afterwards Abbé de Saint-Cyran.

After taking his degree he went to Paris, partly to improve his health by a change of scene, partly to study Greek. Eventually he joined Du Vergier at his country home near Bayonne, and spent some years teaching at the bishop's college. All his spare time was spent in studying the early Fathers with Du Vergier, and laying plans for a reform of the Church.