Declaration of independence

A declaration of independence is an assertion of the independence of an aspiring state or states. Such places are usually declared from part or all of the territory of another nation or failed nation, or are breakaway territories from within the larger state. Not all declarations of independence are successful and result in independence for these regions.

Such declarations are typically made without the consent of the associated state or union, and hence are sometimes called unilateral declarations of independence (UDIs), particularly by those who question the declarations' validity.
Source Wikipedia

List of declarations of independence