Condominium (international law)

A condominium (plural either condominia, as in Latin, or condominiums) in international law is a territory (such as a border area or a state) in or over which multiple sovereign powers formally agree to share equal dominium (in the sense of sovereignty) and exercise their rights jointly, without dividing it into "national" zones.

Although a condominium has always been recognized as a theoretical possibility, condominia have been rare in practice. A major problem, and the reason so few have existed, is the difficulty of ensuring co-operation between the sovereign powers; once the understanding fails, the status is likely to become untenable.

The word is recorded in English since 1718, from Modern Latin, apparently coined in Germany c. 1700 from Latin con- 'together' + dominium 'right of ownership' (compare domain). A condominium of three sovereign powers is sometimes called a tripartite condominium or tridominium.