Cyprus entered the Empire under rather unusual circumstances in 1878. The Ottoman Empire had just been at war with Russia and were very much in danger of losing control of their capital Constantinople. The British intervened in the crisis on the side of the Ottoman Turks by sending a fleet to intimidate the Russians. The Ottoman Sultan was so thankful for the British intervention that he granted the control of the island of Cyprus to the British under the Cyprus Convention.
The timing was quite auspicious for the British, the Suez Canal had opened less than a decade before and so the sea-borne traffic in the Eastern Mediterranean was rising substantially. Much of this traffic was British en route to or from India. Some 4 years later, the British would use the island as a major base of operations for the invasion and occupation of Egypt. This would confirm Britain's growing dominance of the Eastern Mediterranean and Cyprus' role would rise commensurate with that influence. By 1906 the major harbour at Famagusta had been completed for this purpose.
The British were supposed to be running Cyprus on behalf of the Ottomans, but this informal agreement would be unsubtly ended at the outbreak of World War One, when the Turks and British found themselves on opposing sides. Indeed many of the Greek Cypriots on the island, as British subjects, joined the British Army and fought against the Ottomans. The island itself was a useful base of operations against the Turks. It became a particularly useful staging area for the Dardanelles campaign.
Cyprus was declared to be a Crown Colony in 1925. It kept the original Legislative Council that had been formulated in 1882. The Greek majority found that it could not break the constitutional deadlock as the Turkish minority would side with the British appointed representatives. Riots broke out in 1931 over the imposition of certain taxes. This would result in the death of six civilians and the burning down of the British Government house in Nicosia. The constitution would be suspended as a result and direct rule imposed.
In World War Two, the Greek population would rally whole heartedly behind the British - especially after the Italian invasion of mainland Greece and the subsequent arrival of German forces there. Some 30,000 islanders volunteered to fight for the British. The island itself was actually spared much of the fighting apart from air raids. It would remain in British possession and would prove an invaluable staging and refuelling post and would ensure that the Eastern end of the Mediterranean remain reasonably secure for the British.
The island took on a new strategic importance for the British after Egypt became independent in 1952. Cyprus' strategic situation near to an increasingly volatile Middle East and not far from the Suez Canal shipping lanes. Even after the 1956 Suez debacle (much of which was coordinated from Cyprus), it still provided a useful monitoring station and also played a role in the developing Cold War and supporting NATO allies like Turkey and Greece despite their difficulties with one another. The Soviet Union's currying of favour with various Middle Eastern regimes in the 1950s and 1960s combined with its Black Sea Fleet in the region meant that Cyprus was well placed to provide surveillance, intelligence and military responsiveness in the Eastern Mediterranean.
Rising Greek nationalism in the post war period saw political tensions rise as the Greek Cypriots on the island wanted to unite with Greece, whilst the Turkish Cypriots were equally keen to join with Turkey. Riots became increasingly violent as the British themselves resisted claims from both sides in order to keep their important military bases there and to try and keep one group being subjugated by the other. From 1955, the Greek Cypriot EOKA started a campaign of violence to speed up the process for some form of independence. The British responded in November of that year by declaring a State of Emergency.
Much of the strategic rationale for maintaining Cyprus would disappear after the Suez Canal debacle in 1956 which saw Britain climb down from their invasion of the canal zone. In many ways this event marked the beginning of the end of the British Empire in Africa and the Middle East. Consequently nationalists on the island of Cyprus took heart and increased their demands for independence. Although the intractable demands of the two major constituencies made these negotiations particularly difficult.
In the end, the British negotiated to keep their military bases as sovereign areas on the island whilst ceding control to an independent island which allocated government posts and public offices by ethnic quota. However, this arrangement did not last long into independence. Ethnic divisions would make themselves obvious and would eventually result in the division of the island in 1974. The British military presence did remain though and this has continued right up to the present day.