Following an insurgency in the region, Britain withdrew from Aden completely and the two protectorates were merged, gaining independence as South Yemen in 1967. Communists took over in 1969, renaming the country the 'People's Democratic Republic of Yemen', and abolishing the traditional semi-autonomy of the sultan of Mahra.[6] North Yemen at this time remained a separate country. South Yemen's border with Oman remained undemarcated, and relations between the two states worsened during the Dhofar Rebellion, as South Yemen allowed the Communist Dhofari insurgents to base themselves in their territory, resulting in several cross-border skirmishes.[7] Relations improved in the 1980s, with the two countries re-establishing diplomatic relation in 1983.[8]