At the beginning of 2011 a colloquium was held in Ars, France on the theme: "Priestly Celibacy: Foundations, Joys and Challenges". The Cardinal Prefect of the Congregation for the Clergy, gave a series of talks on the teachings of the Popes from Pius XI to Benedict XVI.
1. Pius XI and Ad Catholici Sacerdotii
2. Pius XII and Sacra Virginitas
3. John XXIII and the Encyclical Sacerdotii Nostri Primordia
4. Paul VI and Sacerdotalis Caelibatus
5. John Paul II and Pastores Dabo Vobis
6. Benedict XVI and Sacramentum Caritatis