Allegiance
late Middle English: from Anglo-Norman French, variant of Old French ligeance, from lige, liege (see liege), perhaps by association with Anglo-Latin alligantia ‘alliance’.
wiktionary
From Middle English aliegiaunce, from Anglo-Norman alegaunce(“loyalty of a liege-servant to one's lord”), variant of Old French ligeance, from lige(“vassal, liegeman”). More at liege.
etymonline
allegiance (n.)
"ties or obligations of a citizen or subject to a government or sovereign," late 14c., formed in English from Anglo-French legaunce "loyalty of a liege-man to his lord," from Old French legeance, from liege (see liege (adj.)). Corrupted in spelling by confusion with the now-obsolete legal term allegeance "alleviation, mitigation" (for which see allay (v.)). General figurative sense of "recognition of claims to respect or duty, observance of obligation" is attested from 1732. French allégeance in this sense is said to be from English.
