Succession of states is a theory and practice in international relations regarding the recognition and acceptance of a newly created sovereign state by other states, based on a perceived historical relationship the new state has with a prior state. The theory has its root in 20th century diplomacy. The term succession in international law does not have its normal meaning in English, which would imply automatic inheritance by the new state of the rights and obligations of the prior state. On the contrary, a successor state is a totally new state. This is distinct from a continuing state, also known as a continuator, which despite change to its borders maintains the same legal personality and possess all its existing rights and obligations (such as a rump state).
Consequent upon the acquisition of international personality, the difficult matter of succession to treaty rights and obligations inevitably arises. Succession may refer to the transfer of rights, obligations, and/or property from a previously well-established prior state (the predecessor state) to the new one (the successor state). Transfer of rights, obligations, and property can include overseas assets (embassies, monetary reserves, museum artifacts), participation in treaties, membership in international organizations, and debts. Often a state chooses piecemeal whether or not it wants to be considered the successor state. A special case arises, however, when the predecessor state was signatory to a human rights treaty, since it would be desirable to hold the successor state accountable to the terms of that treaty, regardless of the successor state's desires.
In an attempt to codify the rules of succession of states the Vienna Convention on Succession of States in respect of Treaties was drafted in 1978. It entered into force on November 6, 1996.