In the 1960s and 70s, in the countries of the Arab-Muslim East, various theories of "national brands of socialism", named "Islamic socialism", became widespread. This socialism was based on the principles of nationalism, religion and equality, and its ideas inspired a number of revolutions, popular uprisings and coups in the Arab world. Similarly, in Libya, on 1 September 1969 a group of Libyan army officers belonging to the Movement of Free Officers, Unionists, and Socialists overthrew the monarchy and proclaimed the Libyan Arab Republic. The supreme power was temporarily relegated to the Revolutionary Command Council (RCC), headed by 27-year-old Colonel Muammar Gaddafi.