One of the key members of the group that formed around Apollinaire, a painter as well as a poet, Jacob lived in extreme poverty, working all manner of jobs throughout his life. Although born Jewish, he converted to Catholicism in 1915, six years after having a vision of Christ. In 1921 he moved from Paris to the small village of Saint Benoit-sur-Loire, close to a Benedictine church, where he remained until his arrest by the Nazis in February1944. He died of bronchial pneumonia the following month in a concentration camp at Drancy, near Paris.