allegiance
n.a person's loyalty or support for a leader, a country, or a group.
n.the loyalty or commitment of a subordinate to a superior or of an individual to a group or cause.
“The soldiers swore an oath of allegiance to their country.”
“In many modern democracies, citizens do not have to prove their allegiance to a specific political party to vote.”
“The shifting geopolitical landscape forced smaller nations to reconsider their traditional allegiance to the former empire, seeking instead to form new regional alliances for economic security.”
Often used with the verb 'swear' or 'pledge'; typically takes the preposition 'to'.
The noun 'allegiance' almost always takes the preposition 'to' rather than 'for'.
From Middle English alegiaunce, 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.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.