FIDEICOMMISSUM (fideicommissum). — It is the disposition by last will by which an heir is instituted with the obligation to preserve and transmit, in whole or in part, the inheritance to a specified person or entity. The heir is called the fiduciary; the person or entity for whom the inheritance is to be preserved and to whom it is to be transmitted is called the fideicommissary.
The institution of the fideicommissum dates back to Roman law (Inst. Inst., 1, II, tit. 23, de fideicom. heredit. § 2). It was widely applied in the Middle Ages and after 1500, also due to the influence of Spanish legislation. The nobility first and then the bourgeoisie made extensive use of it to ensure the preservation of patrimony and other assets (e.g., shops, industries, etc.) within the family—even to the point of primogeniture.
The principles of freedom, affirmed especially with the French Revolution, gradually led to the abolition of the institution of the fideicommissum. The Civil Code of 1865, in article 899, excluded any fideicommissary substitution, whereas the current Code of 1942 reinstates it exclusively within these limits: a) the testator may impose on the child the obligation to preserve and return, upon his death, in whole or in part, the assets constituting the disposable portion to all the children born or to be born to him or to a public entity (art. 692); likewise, the testator may impose on a brother or sister the obligation to preserve and return the assets left, to all the children born or to be born to them or to a public entity (art. 692). The fiduciary heir assumes somewhat the role of a usufructuary, with the enjoyment, free administration, and representation of the assets that form the trust (art. 693). The inheritance devolves to the substitute at the time of the death of the fiduciary (art. 696).
Fideicommissary substitution in favor of pious causes is admitted without limits by canon law (can. 1513-14), which prescribes that the cleric or religious fiduciary (when the trust is in favor of pious causes) inform the Ordinary, who, as ex officio guardian of pious intentions (can. 1515 § 1), will exercise control (can. 1516). In canon law, fideicommissary substitution may also occur by inter vivos act.