As Great Britain planned for the eventual independence of South Arabia in the 1960s, Qu'aitis declined to join the British-sponsored Federation of South Arabia but remained under British protection as part of the Protectorate of South Arabia. Despite promises of a UN referendum to assist in determining the future of the Qu'aiti State in South Arabia on 17 September 1967, communist forces overran the kingdom and, in November of that year, the Qu'aiti State was integrated forcibly without a referendum into communist South Yemen. South Yemen united with North Yemen in 1990, again without a referendum, to become the Republic of Yemen.