The act of giving benefices in commendam (in trust) or the condition of such during the absence of a titular authority. The practice existed in the early Church and became common especially during the barbarian invasions (see Gregory I, Reg. 2.37 [Ewald 1:132]). Essentially it was a temporary arrangement. The holder drew the revenue during the vacancy and exercised some jurisdiction. Subsequently, from the Carolingian period onward, the practice fell into disrepute when it was used to reward those who clearly could not fulfill the duties (e.g., granting an abbey to a layman) and when it lost its temporary character. These developments were part of the feudalization of ecclesiastical institutions during the Middle Ages. Attempts were made to remedy the situation (cf. lyons council II, c.14 [Conciliorum oecumenicorum decreta 298] and lateran council V, Supernae dispositionis arbitrio [Conciliorum oecumenicorum decreta 59]), but the papacy found the system useful, and it was flagrantly abused, especially during the financial crises of the later Middle Ages. The practice of giving commendatory abbeys continued after the Reformation and lasted into the 18th and 19th centuries.
Bibliography: r. laprat, Dictionnaire de droit canonique, ed. r. naz, 7 v. (Paris 1935–65) 3:1029–85. g. mariÉ, Catholicisme. Hier, aujourd'hui et demain, ed. g. jacquemet (Paris 1947– ) 2:1340–42. p. hofmeister, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner, 10 v. (2d, new ed. Freiburg 1957–65) 6:407. h. e. feine, Kirchliche Rechtsgeschichte, v. 1 Die katholische Kirche (4th ed. Cologne 1964).
"Commendation." New Catholic Encyclopedia. . Encyclopedia.com. (December 17, 2018). https://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/commendation
"Commendation." New Catholic Encyclopedia. . Retrieved December 17, 2018 from Encyclopedia.com: https://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/commendation