On September 27, 1540, Pope Paul III issued the bull Regimini militantis ecclesiae, approving the foundation of the Society of Jesus. It had been presented by Ignatius of Loyola and his first companions, and the bull limited the new order to sixty members, which was raised to unlimited in 1543. There were ten Jesuits.
Ignatius was 49 and had come to it late and by a strange route. He was a Basque nobleman, a soldier, whose leg was shattered by a French cannonball at the siege of Pamplona in 1521, and who read the lives of the saints while he was recovering and decided to do what they had done. He spent ten months in a cave at Manresa, went to Jerusalem, came back and studied, first at Barcelona, then Alcala, then Salamanca, where he was twice imprisoned by the Inquisition and questioned about his preaching, and finally Paris.
The group that formed around him at the University of Paris was the founding: Francis Xavier, Peter Faber, Diego Lainez, Alfonso Salmeron, Nicolas Bobadilla, Simon Rodrigues, and later Claude Jay, Jean Codure and Paschase Broet. They took vows at Montmartre in August 1534, adding a promise to go to Jerusalem or, failing that, to place themselves at the pope's disposal.
Its design was new. The Jesuits had no distinctive habit and no obligation to the divine office in common, which freed them from the timetable that kept monks in their houses. They took a fourth vow, of obedience to the pope in matters of mission. Their training was long, about fifteen years, with heavy weight on philosophy and theology, and their novitiate ended with the thirty-day retreat based on Ignatius's Spiritual Exercises.
The result was the most effective instrument the Catholic Reformation had. Jesuits ran the Council of Trent, where Lainez and Salmeron were the pope's theologians. They ran schools: by 1600 there were about 200 Jesuit colleges, and by the suppression in 1773 about 800, and a student at one of them was educated rather than merely instructed. They ran missions: Xavier, who died off the coast of China in 1552, had baptised tens of thousands in India and Japan; Matteo Ricci entered China in 1583 and the Jesuits were at the Ming and Qing courts for two centuries.
Its history was turbulent. It was suppressed by Clement XIV in 1773, survived in Russia, and was restored in 1814. It has produced about 50,000 members at its peak, and about 14,000 now, running schools, universities and parishes in about 100 countries.