Originally colonized in the 6th cent. b.c. by the Greeks, the region later came under Roman and Byzantine rule. In the 8th cent. a leader of the Abkhaz tribe formed an independent kingdom that became part of Georgia in the 10th cent. In 1578 the Turks conquered the area and gradually converted it to Islam. By a treaty with the Abkhazian dukes, Russia acquired Sukhumi in 1810 and declared a protectorate over all Abkhazia, which was formally annexed in 1864.

Abkhazia became an autonomous republic of the Soviet Union in 1921 and was made part of Georgia in 1930. In 1991 the region became an autonomous republic inside independent Georgia. Georgia itself was soon torn apart by bitter fighting between government forces and a guerrilla movement seeking an independent Abkhazian state. More than 3,000 people were killed in the fighting, and some 250,000 people, mostly ethnic Georgians, fled. In 1994 a cease-fire was negotiated, with Russian troops serving as peacekeepers, but the ultimate disposition of Abkhazia remained unresolved and fighting broke out again in 1998 and in 2001. In a 1999 referendum regarded as illegal by Georgia, voters approved declaring the region a sovereign state. The area is heavily dependent on Russia, and most of the residents now hold Russian passports.

After a presidential election in Oct., 2004, that apparently ended in a slim victory for opposition candidate Sergei Bagapsh, allegations of fraud from the Russian-supported runner-up, Prime Minister Raul Khajimba, resulted in a call for a new election, and a governmental impasse ensued. The issue was resolved when Bagapsh, who was widely believed to have won despite fraud on Khajimba's side, agreed to a new election (Jan., 2005) in which Khajimba was his running mate. Russia's failed attempt to manipulate a presidential victory for Khajimba, despite Bagapsh's own pro-Moscow leanings, was generally seen as a significant blunder.

In the aftermath of Georgia's attack on South Ossetia in Aug., 2008, and Russia's counterattack, Russia positioned additional troops in Abkhazia and for a time occupied some neighboring sections of Georgia. Abkhazian forces also seized the Kodori gorge, a region of Abkhazia that had remained under Georgian control. Subsequently Russia recognized Abkhazia as independent; a few other nations also have since done so. Russian and Abkhazian forces did not withdraw from areas of Abkhazia not previously under Abkhazian control, as called for in the truce, and Russia later began building several military bases in Abkhazia. Bagapsh was reelected in 2009. When he died in 2011, Aleksandr Ankvab became acting president and then was elected president.