Definition of alliance:
(n) :
the state of being allied; the act of allying or uniting; a union or connection of interests between families, states, parties, etc., especially between families by marriage and states by compact, treaty, or league; as, matrimonial alliances; an alliance between church and state; an alliance between France and England; any union resembling that of families or states; union by relationship in qualities; affinity
"the alliance of the principles of the world with those of the gospel. --C. J. Smith."