Council of Trent: Session 25
Chapter 20
Superiors of orders not subject to bishops shall visit and correct inferior Monasteries, even though held in commendam.
Abbots, who are heads of orders, and the other Superiors of the aforesaid orders, who are not subject to bishops, but have a lawful jurisdiction over other inferior monasteries, or priories, shall, each in his own place and order, visit officially the said monasteries and priories that are subject to them, even though held in commendam: which, for as much as they are subject to the heads of their own orders, the holy Synod declares that they are not to be included in what has been elsewhere decreed relative to the visitation of monasteries held in commendam; and those who preside over monasteries of the orders aforesaid shall be bound to receive the above-named visitors, and to execute their orders.
Also, those monasteries themselves which are the heads of orders, shall be visited conformably to the constitutions of the holy Apostolic See, and of each several order. And so long as the said commendatary monasteries shall continue, there shall be appointed, by the general Chapters, or by the visitors of the said orders, priors claustral, or sub-prior in those priories that are conventual, who shall exercise spiritual authority, and correction. In all other things the privileges and faculties of the above-named orders, as regards the persons, places, and rights thereof, shall remain firm and inviolate.
Chapter 21
Over Monasteries, Religious of that same order shall be appointed.
Whereas very many monasteries, even abbeys, priories, and provostries, have suffered no slight injury, both in spirituals and temporals, through the mal-administration of those to whom they have been entrusted, the holy Synod would fain by every means restore them to a discipline suitable to a monastic life. But the present state of the times is so fraught with hindrances and difficulties that a remedy can neither be applied at once to all, nor common to all places, as It could desire; nevertheless, that It may not omit anything which may in time be used in wholesomely providing against the evils aforesaid, It trusts in the first place, that the most holy Roman Pontiff will, of his piety and prudence, make it his care,—as far as he sees that the times will permit,—that over those monasteries which are at present held in commendam, and which are conventual, there be appointed Regulars, expressly professed of the same order, and capable of guiding and of governing the flock. And as to such as shall become vacant hereafter, they shall be conferred solely on Regulars of distinguished virtue and holiness. But as regards those monasteries which are the heads and chiefs of orders, be the filiations thereof called abbeys or priories, those who hold them at present in commendam shall be bound,—unless provision be made for a Regular successor thereunto,— either to make, within six months, a solemn profession of the religious life which is peculiar to the said orders, or to resign; otherwise the places aforesaid held in commendam shall be accounted ipso jure vacant. But, lest any fraud may be used as regards all and singular the aforesaid matters, the holy Synod ordains, that in the appointments to the said monasteries, the quality of each individual be specifically expressed; and any appointment made otherwise shall be accounted surreptitious, and shall not be rendered valid by any subsequent possession, even though extending over three years.