He wanted to create a unified Arab state from Syria to Yemen
.On June 10, 1916, in World War I, Sharif Hussein bin Ali fired the first symbolic shot from his palace towards the Jeroul Turkish military base in Mecca; thus launching the Arab revolt against the Ottoman Government of the Committee of Union and Progress (CUP). The aim of the revolt, as put in Sharif Hussein’s almost 2,500-word declaration on June 26, 1916 was the “complete separation and the independence of the Hijaz, the Arabs, and Arab countries from the Ottoman Empire."
Also Great Britain was the main supporter behind the revolt militarily and financially.