Trinoda

Before the coming of the Conqueror and his feudal lawyers much land in England had been acquired to be held by the spiritual tenure of frankalmoign, a tenure subjecting the holders to what was termed the trinoda necessitas f (or threefold obligation) of repairing highways, building castles, and repelling invasions, but otherwise to no service other than praying for the souls of the donor and his heirs, dead or alive (Stephen, op. cit., ❋ 1840-1916 (1913)

Probably the most important were military service (_fird_, _expeditio_) and the repairing of fortifications and bridges -- the _trinoda necessitas_ of later times. ❋ Various (N/A)

The _trinoda necessitas_, so much spoken of, which was to attend the king in his expeditions, and to contribute to the building of bridges and repair of highways, never bound the lands by way of tenure, but as a political regulation, which equally affected every class and condition of men and every species of possession. ❋ Edmund Burke (1763)

The keeping of the roads in repair, one part of the _trinoda necessitas_ was imposed on all lands; but the results often seem to have been very indifferent, and they appear largely to have depended on chance, or the goodwill or devotion of neighbouring landowners. [ ❋ Unknown (1893)

The "trinoda necessitas," as it was called, or the burden of military expeditions, of repairing highways, and of building and supporting bridges, was inseparable from landed property, even though it belonged to the church or monasteries, unless exempted by a particular charter. [ ❋ David Hume (1743)