Citing the Treaty of Guarantee as the basis for its action, Turkey launched its seaborne assault west of Kyrenia on July 20, 1974. About 6,000 men participated in the landing force, which was followed shortly afterwards by about 1,000 paratroopers dropped north of Nicosia. Turkish Cypriot irregulars joined the Turkish regulars in both areas, but they faced fierce opposition from the National Guard. Kyrenia did not come under Turkish control until heavy sea and air bombardment drove out Greek Cypriot troops on the third day of fighting. Meanwhile, Turkish Cypriot enclaves throughout the southern part of the island fell to Greek Cypriot forces. Only in Nicosia was the Turkish Cypriot enclave successfully defended by TMT irregulars, with the aid of the Turkish Air Force.

When a UN-imposed cease-fire took effect on July 22, Turkish troops held a triangular area in northern Cyprus with Kyrenia in the center of its base along the coast and northern Nicosia at its apex. Clear Turkish superiority in personnel and equipment deterred Greek leaders from intervening. Nearly half the Turkish Cypriot population lay outside the occupied area, in enclaves now controlled by the National Guard. During the next three weeks, while foreign ministers from Britain, Greece, and Turkey met in Geneva, Turkish troops continued to seize control of areas outside the cease-fire lines, broadening the triangle under their occupation. Their troop strength was augmented through the Kyrenia bridgehead to some 40,000 soldiers and 200 tanks.

On August 14, immediately on the breakup of the second round of Geneva talks, two divisions of the Turkish Army advanced beyond their cease-fire positions. During the three-day offensive, Greek Cypriot resistance crumpled under heavy air, armor, and artillery bombardment. Civilians, alarmed by reports of atrocities during the first Turkish campaign, fled ahead of the advancing troops, who proceeded unimpeded through much of northern Cyprus. By August 16, the Turkish advance had reached the predetermined "Attila Line," behind which troops occupied 37 percent of Cypriot territory, and Turkey ordered a cease-fire (see fig. 1, Administrative Divisions, 1991). Although authoritative figures on casualties were not published, it was estimated that Greek Cypriot forces suffered 6,000 casualties, while Turkish-led forces lost 1,500 dead and 2,000 wounded.

Data as of January 1991