Annul comes from Late Latin annullāre (to make nothing), a compound of ad- (to) and nullus (none), and has served as a core term of legal cancellation since the 14th century.
To declare legally invalid or void; to abolish or cancel an official agreement or decision
Annul entered Middle English in the late 14th century from Old French anuller, from Late Latin annullāre, meaning 'to make nothing.' The Late Latin verb is a compound of ad- (to) and nullum (nothing), the neuter of nullus (not any), which itself is a contraction of ne- (not) and ullus (any). The original sense was strictly legal: to
Henry VIII's break with Rome in 1533 hinged on the word 'annul.' When Pope Clement VII refused to annul Henry's marriage to Catherine of Aragon, the king declared himself Supreme Head of the Church of England — a constitutional revolution triggered by a dispute over whether a marriage could be made null.