A British protectorate under Ottoman suzerainty was established over Cyprus by the Cyprus Convention of 4 June 1878, following the Russo-Turkish War, in which the British occupied the island as a consequence of the Ottoman Empire's actions throughout the duration of the war. Cyprus was then proclaimed a British protectorate and was integrated into the British Empire. This remained in place until November 1914, when after the Ottomans joined the Central Powers, in turn entering World War I, Britain declared the complete annexation of Cyprus into the British Empire, albeit under a military administration status. The colony of British Cyprus was proclaimed a decade later, in 1925, after Britain's annexation of Cyprus was verified twice, firstly in the Treaty of Sevres in 1920, then confirmed again in the Treaty of Lausanne in 1923.
Queen Elizabeth II was the last Sovereign of British Cyprus until it became a republic on 16 August 1960.