Mariology of the popes John Paul II), visits to Marian shrines (Benedict XVI in 2007) and by actively supporting the fathers of Vatican II as they highlighted the importance of Marian veneration (Popes John XXIII and Paul VI) in "Lumen gentium". Popular views like the Assumption and the Immaculate Conception developed into papal teaching over time. Popes have also limited and cautioned against some devotional practices. In 1674 Pope Clement X (1670–1676) indexed books on Marian piety. After the Council of Trent, "Marian fraternities" were founded, fostering Marian piety, not all of which were approved. Not all Popes took the same view on Marian
Mariology of the popes and the veneration of the Blessed Virgin. They made decisions not only in the area of Marian beliefs (Mariology) but also Marian practices and devotions. Popes promulgated Marian veneration and beliefs by authorizing: new Marian feast days, Marian prayers and initiatives, acceptance and support of Marian congregations, indulgences and special privileges, and support for Marian devotions. The formal recognition of Marian apparitions (such as at Lourdes and Fatima) has also been influential. Since Pope Leo XIII, popes have promoted Marian devotion through encyclicals, Apostolic Letters and with two dogmas (Immaculate Conception and Assumption), the promulgation of Marian years (Pius XII,