Self-proclaimed state

A number of polities have declared independence and sought diplomatic recognition from the international community as de jure sovereign states, but have not been universally recognised as such. These entities often have de facto control of their territory. A number of such entities have existed in the past.

There are two traditional doctrines that provide indicia of how a de jure sovereign state comes into being. The declarative theory defines a state as a person in international law if it meets the following criteria:

According to the declarative theory, an entity's statehood is independent of its recognition by other states. By contrast, the constitutive theory defines a state as a person of international law only if it is recognised as such by other states that are already a member of the international community.

Proto-states often reference either or both doctrines in order to legitimise their claims to statehood. There are, for example, entities which meet the declarative criteria (with de facto partial or complete control over their claimed territory, a government and a permanent population), but whose statehood is not recognised by any other states. Non-recognition is often a result of conflicts with other countries that claim those entities as integral parts of their territory. In other cases, two or more partially recognised states may claim the same territorial area, with each of them de facto in control of a portion of it (as have been the cases of the Republic of China (Taiwan) and the People's Republic of China (PRC), and North and South Korea). Entities that are recognised by only a minority of the world's states usually reference the declarative doctrine to legitimise their claims.

...
Wikipedia