Peter Canisius was a Dutch Jesuit priest. He became known for his strong support for the Catholic faith during the Protestant Reformation in Germany, Austria, Bohemia, Moravia, Switzerland and the British Isles. The restoration of the Catholic Church in Germany after the Protestant Reformation is largely attributed to the work there of the Society of Jesus, which he led. He is venerated in the Catholic Church as a saint and as a Doctor of the Church.

The Society of Jesus, also known as the Jesuit Order or the Jesuits, is a religious order of clerics regular of pontifical right for men in the Catholic Church headquartered in Rome. It was founded in 1540 by Ignatius of Loyola and six companions, with the approval of Pope Paul III. The society is engaged in evangelization and apostolic ministry in 112 nations. Jesuits work in education, research, and cultural pursuits. Jesuits also conduct retreats, minister in hospitals and parishes, sponsor direct social and humanitarian ministries, and promote ecumenical dialogue.