The indult for the Tridentine Mas was granted in October, 1984 by His Holiness Pope John Paul II, in the document *Quattuor Abninc Annos. *This indult permitted the celebration of Mass according to the 1962 edition of the missal of St. Pius V, which was promulgated in 1570, after the Council of Trent. The indult stated that such celebrations could be held where the local ordinary, i.e., the bishop, permitted them. Thus, the indult was given by the Holy See, but its application is made at the discretion of the ordinary.
Few bishops responded affirmatively to this indult, enough so that the papal motu proprio announcing the Lefebvre excommunication in 1988 called for “a wide and generous application” of the 1984 indult. To this end, a ponftifical commission was formed to oversee matters pertaining to the indult. The commission, which still functions today, takes its name from that 1988 document that provided for the expanded use of the indult, Ecclesia Dei.