Old Eng. Hist. Usually erron. trinoda n. [Late L., = trimoda, fem. of trimodus adj. ‘of three kinds,’ (Isidore, Orig., II. xvii., De trimodo dicendi genere), f. TRI- + modus mode, manner, necessitas necessity, exigency, need, obligation.
The phrase occurs only once, viz. in an OE. Charter attributed to K. Cædwalla of Wessex, 685–8, but actually in a MS. of about 975. Thence erroneously cited in 1614 by Selden as trinoda necessitas, whence in other 17th-c. legal antiquaries and dictionaries, and thence in 19th-c. historians and legal writers, and usually taken to mean three-knotted from L. nōdus knot. See article by W. H. Stevenson in Eng. Hist. Rev., Oct., 1914; also G. J. Turner, in Encycl. Brit. (ed. 11), XXVII. 287/1.]
A collective appellation for the three great obligations upon land-holders in Anglo-Saxon times, of maintaining bridges and fortresses, and rendering military service, in OE. brycgbót, burhbót, and fyrd. (There was no collective OE. term for the three.)
c. 975. Charter of Cædualla, an. 680, in Kemble, Cod. Dipl., I. 24. Ego cædualla rex … hanc donationis meæ cartulam scribere iussi, et absque trimoda necessitate totius christiani populi, id est arcis munitione, pontis emendatione, exercitii congestione, liberam perstrinxi.
1614. Selden, Titles of Honor, II. viii. 301. Those three; repairing of Bridges, Tax for Warre, and Castle gard, or repairing them: as of what no land should or could be discharged. They are called by a speciall name Trinoda Necessitas in a Patent by K. Cedwalla to Wilfrid first Bishop of Selesey.
1691. Blount, Law Dict. (ed. 2), Trinoda necessitas, i. Expeditio, Pontis, & Arcis reparatio.
1701. Cowell’s Interpr., Trinoda Necessitas, a threefold necessary Tax or Imposition, to which all Lands were subjected in Saxon Times.
1874. Stubbs, Const. Hist., I. v. 95. The duty of ‘burh-bot,’ which formed part of the trinoda necessitas, and was incumbent on every owner of land, threw the burden of repairing the fortifications on the land-owning townsmen of the particular burh.
1876. Digby, Real Prop., i. 13. The trinoda necessitas, to which all lands were subject.
