Since securing independence from the Ottoman Empire in 1831, Greece claimed Cyprus due to its majority Greek population. Indeed, the new monarch was styled "King of the Hellenes" to emphasize sovereignty over Greeks everywhere. Enosis (union) with Greece was also the aspiration of Greek Cypriots. In 1915 Britain offered to cede Cyprus to Greece in return for their entry into the war against the Central Powers, but Greece considered the price too great as they expected a German victory. Turkey recognised the annexation of Cyprus by Britain in the Treaty of Lausanne in 1923.
This war-time offer by Britain also raised Cypriot expectations since it invalidated the previous British argument that Cyprus was leased from the Turks and would revert to them when the British departed. When Britain made Cyprus a Crown Colony in 1925, the political campaign for enosis intensified.
At conferences in Zurich in 1958 London in 1959 (codified as the Treaty of Guarantee in 1960), the two Cypriot communities, Britain, Greece and Turkey came to a compromise: Cyprus independence with a Greek president ), a Turkish vice president, 70:30 Greek-Turkish representation in parliament and government services, and a proscription on union with Greece or any other state. On 16th August 1960 Cyprus gained independence as a republic within British Commonwealth.
In 1964 the Treaty of Guarantee was abrogated (done away with), and following a state of emergency and a Coup d'etat by Cypriot National Guard in 1974, Turkey invaded Cyprus (twice) to form a Turkish / Greek Cypriot partition on the island which was formalised by UNFICYP who established a buffer zone between Turkish and Greek zones in August 1974, (Turkish Federal State) which was officially ended in Feb 2004. Later that year Greek (Republic) Cyprus joined the European Union, with Turkish (North) Cyprus declining, and remaining unrecognised except by Turkey.