Estados de la Tregua
In 1952, the Trucial States Council was established to encourage co-operation between the seven Rulers. The Indian rupee remained the "de facto" currency of the Trucial States as well as the other Persian Gulf states such as Qatar, Bahrain, Kuwait and Oman until the Gulf rupee was introduced in 1959. The Gulf rupee was used until the Gulf countries introduced their own currencies after the great devaluation of the rupee.