The Vatican on Thursday imposed some of the highest penalties available under the Catholic Church's canon law on a breakaway group that consecrated four bishops in defiance of the pope.

The Congregation for the Doctrine of the Faith, the Catholic watchdog authority, announced that the four newly consecrated bishops, as well as two other bishops, will be expelled from the church or excommunicated.

It also warned that the faithful "who adhere formally" to the group, the Society of Saint Pius X (SPPX), are also considered "schismatic" and therefore excommunicated.

The term schism indicates a severe, formal rupture inside the Catholic ​community, while excommunication excludes an individual from receiving sacraments, getting married according to Catholic rites, or holding church office, among other things.

The moves annul the concessions granted by the Vatican in the past to bring the group, which has long had strained ties with Rome, back into the official Catholic fold.What did the SSPX do?