al ‧ le ‧ giance /əˈliːdʒ ə ns/ BrE AmE noun [uncountable and countable]
[ Date: 1300-1400 ; Language: Old French ; Origin: ligeance , from lige 'person you owe loyal service to' , from Late Latin laetus 'serf' ]
loyalty to a leader, country, belief etc
allegiance to
You owe allegiance (=have a duty to give allegiance) to your king.
swear/pledge allegiance
I pledge allegiance to the flag of the United States of America.
an oath of allegiance
switch/transfer allegiance (=start to support a different person, group etc)
The people here have strong political allegiances.