From Latin 'factum' (a thing done) — only shifted to mean 'a thing known to be true' in the 1600s, with empirical science.
A thing that is known or proved to be true; an actual occurrence or event.
From Latin "factum" (an act, deed, event), neuter past participle of "facere" (to do, to make), from PIE *dʰeh₁- (to put, to place, to do). This prolific root produced one of the largest word families in English: "factory," "manufacture," "affect," "effect," "perfect," "defect," "infect," "confect," "feat," "fashion," "feasible," and "office" (from "opificium," a doing of work). Through the French
The word 'fact' originally meant 'a deed' or 'an action' — especially a criminal one. The legal phrase 'after the fact' (as in 'accessory after the fact') preserves this original sense. The meaning 'a truth about reality' only emerged in the 1630s, during the Scientific Revolution, when empirical observation made 'what actually happened' the standard of knowledge.