Truce
Middle English trewes, trues (plural), from Old English trēowa, plural of trēow ‘belief, trust’, of Germanic origin; related to Dutch trouw and German Treue, also to true.
wiktionary
From Middle English trewes, triwes, trues, plural of trewe, triewe, true(“faithfulness, assurance, pact”), from Old English trēowa, singularized plural of trēow, trȳw(“faith; pledge; agreement”), from Proto-Germanic *trewwō (compare Dutch trouw, German Treue, Danish tro), noun form of *triwwiz(“trusty, faithful”). More at true.
etymonline
truce (n.)
"mutually agreed-upon temporary intermission of hostilities," early 13c., triws, variant of trewes, originally plural of trewe "faith, assurance of faith, covenant, treaty," from Old English treow "faith, truth, fidelity; pledge, promise, agreement, treaty," from Proto-Germanic *treuwo- (source also of Old Frisian triuwe, Middle Dutch trouwe, Dutch trouw, Old High German triuwa, German treue, Gothic triggwa "faith, faithfulness"), from PIE root *deru- "be firm, solid, steadfast." Related to true (adj.). The Germanic word was borrowed into Late Latin as tregua, hence French trève, Italian tregua.
