Bible Encyclopedias
Libelli Pacis or Letters of Peace.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature

In Egypt and Africa many of those who had fallen away in time of persecution, in order the more readily to obtain pardon for their offenses, resorted to the intercession of persons destined to suffer martyrdom by securing from them libelli pacis, letters of peace; papers in which these returning apostates were commended as worthy of communion and Church membership. In this way they were again taken into communion sooner than the rules of the Church otherwise allowed. From this practice the pope claims a precedent for the exercise of his pretended power to grant spiritual indulgences, which seem to have been used first about the middle of the second century. See Farrar, Eccles. Dict. s.v.; Mosheim, Commentary (see Index). (See INDULGENCES); (See LAPSED).

Bibliography Information
McClintock, John. Strong, James. Entry for 'Libelli Pacis or Letters of Peace.'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. https://www.studylight.org/​encyclopedias/​eng/​tce/​l/libelli-pacis-or-letters-of-peace.html. Harper & Brothers. New York. 1870.