Traditionalist Catholicism is a movement of Catholics in favour of restoring many or all of the customs, traditions, liturgical forms, public and private devotions and presentations of the teaching of the Catholic Church before the Second Vatican Council (1962–65). They are commonly associated with an attachment to the eucharistic liturgy often called the Tridentine, Traditional Latin or extraordinary form of the Mass.
In general, Traditionalist Catholics were disturbed by the liturgical transformations of the Second Vatican Council, arguing that it stripped the liturgy of its outward sacredness and made it too Protestant. Many also oppose the social teachings that came into the Church during and after the Council, such as ecumenicalism, claiming that it blurs the lines between Catholicism and other religions.
The traditionalist movement traces its roots to at least the early 1970s, where conservative Catholics opposed to or uncomfortable with the social and liturgical changes brought about by Second Vatican Council began to coalesce. In 1970, French Archbishop Marcel Lefebvre founded the Society of Saint Pius X (SSPX), made up of priests who would say only the Traditional Latin Mass and who stood opposed to what he saw as excessive liberal influences in the Church. Overtime, Lefebvre's movement grew and split into various offshoot groups. Some Catholics took the position of sedevacantism, which teaches that all the popes since John XXIII are heretics, and that the new Church and new expressions of the sacraments are not valid. Other, smaller groups known as conclavists have elected their own popes in opposition to the men generally considered by the world to be the true popes. The Society of Saint Pius V (SSPV) broke off from Lefebvre over its objections to the SSPX's use of the missal of Pope John XXIII, preferring the much older 1570 missal of Pope Pius V, and publicaly questioning the legitimacy of the post-Vatican II popes. Lefebvre officially renounced these positions, but his movement still drew the suspicion of Roman authorities. In 1988, he and another bishop consecrated four men as bishops without papal permission, resulting in an Latae sententiae excommunication for all six men directly involved. Some members of his society, unwilling to participate in what they considered schism, left and founded the Priestly Fraternity of Saint Peter (FSSP), which celebrates the Latin Mass but in full communion with the Holy See. During the papacy of Pope Benedict XVI, numerous attempts were made to bring the SSPX back into communion with the Church, including the lifting of the excommunications on the four surviving bishops. These failed, but the efforts of the SSPX to negotiate with Rome led to the establishment of the SSPX Resistance.