In 1960, when Cyprus became independent, the Treaty of Guarantee between Greece, Turkey, Cyprus, and the UK was signed. It stated that Cyprus would not form any political or economic union with any other state (AI), that the signatories would respect the territorial integrity and independence of Cyprus (AII), and that a signatory could take action to maintain the current state of affairs in Cyprus (AIV).

In 1974, the Greek ruling military junta organized a coup in Cyprus in which they placed Nikos Sampson as dictator of Cyprus. Sampson was in favor of Enosis, that is "union" with Greece. Turkey claimed that this coup would imminently lead to Enosis, which would violate AI of the Treaty of Guarantee. Under the powers granted to it under AIV, Turkey invaded Cyprus in order to prevent Enosis and maintain the current state of affairs. The action helped cause the fall of the Greek junta and the establishment of the Third (and current) Hellenic Republic.

Turkey's action led to population exchanges between the north and south of Cyprus. Prior to it, Greek Cypriots lived throughout Cyprus, while Turkish Cypriots lived mostly in enclaves also throughout Cyprus. Turkey's invasion led to Greek Cypriots moving south and Turkish Cypriots moving north. Turkey established the Turkish Republic of Northern Cyprus, which is still not recognized today. It also started supporting Anatolian Turks who settled in Northern Cyprus.