According to the Commonwealth’s charter, member states should communicate and co-operate “in the common interests of our peoples and in the promotion of international understanding and world peace”.

In its statement, The Gambian government said it had “withdrawn its membership of the British Commonwealth”.

It said it had “decided that The Gambia will never be a member of any neo-colonial institution and will never be a party to any institution that represents an extension of colonialism”.

[…]

The last time a nation left the Commonwealth was in 2003, when Zimbabwe withdrew.

BBC News.