Fighting in Georgia's breakaway region of South Ossetia in August caused dozens - possibly hundreds - of deaths and widespread destruction.
Georgian, Russian and South Ossetian forces were all involved. There were also clashes in Abkhazia, and Russian attacks on other parts of Georgia.
The separatist administrations in South Ossetia and Abkhazia have been trying to gain formal independence since breaking away in the early 1990s. Russia has now recognised them as independent - a move condemned by Western nations.
Tensions in both regions began to escalate after Mikheil Saakashvili was elected Georgian president in 2004, on a promise to re-unite the country.
The conflicts had remained largely frozen, despite occasional flare-ups, before August 2008.
What triggered the crisis?
A series of clashes between Georgian and South Ossetian forces in the summer of 2008 prompted Georgia to launch an aerial bombardment and ground attack on South Ossetia on 7 August.
Georgian forces controlled the South Ossetian capital, Tskhinvali, for part of the following day.
Russia, meanwhile, poured thousands of troops into South Ossetia, and launched bombing raids both over the province and on targets in the rest of Georgia.
There have been unverified reports of war crimes on both sides.
Did the Russian forces enter South Ossetia before or after the Georgian attack?
This is unclear.
Georgia says it began its assault after learning that a large convoy of Russian armour was coming through the Roki tunnel, from North Ossetia into South Ossetia.
Russia says it acted to defend Russian citizens in South Ossetia, and its own peacekeepers stationed in the breakaway region.
How did the conflict develop?
Russian forces occupied parts of Georgia adjoining South Ossetia, including the town of Gori, a strategic town on the main road linking eastern and western Georgia.
They also moved from bases in Abkhazia into parts of western Georgia, and the Russian fleet went into action against the Georgian navy.
Abkhaz forces recaptured the Kodori Gorge - a region of Abkhazia taken by Georgian troops in 2006.
Who are the main casualties?
Large numbers of civilians were driven out of their homes in South Ossetia. Many South Ossetians crossed over to the Russian republic of North Ossetia.
Residents of Georgian villages in South Ossetia, and the town of Gori, also fled.
The heavy fighting left the South Ossetian capital, Tskhinvali, largely in ruins.
Why is Russia involved?
More than half of South Ossetia's 70,000 citizens are said to have taken up Moscow's offer of Russian citizenship. Russia says its actions were designed to protect those citizens.
Russia also had peacekeepers based in South Ossetia. Some of these were killed in the Georgian attack on 7 August.
Until recently, Russia said it respected Georgia's territorial integrity, and only wanted to look out for Russian citizens.
But, following Georgia's military action, Russia recognised the independence of both South Ossetia and Abkhazia on 26 August.
The US and France were swift to condemn Russia's move, calling it "regrettable," while the the UK categorically rejected it. Nato said the declaration violated numerous UN Security Council resolutions that Russia itself had endorsed.
Russia has also signed friendship treaties with the breakaway regions, formalising diplomatic ties and pledging military assistance.
Does Georgia have links to Nato?
President Saakashvili has made membership of Nato one of his main goals - and Nato agreed in April 2008 that Georgia would become a member of the alliance at some unspecified date in the future.
The country has had a close relationship with the United States - sending troops to join the US-led coalition in Iraq.
The US has helped to train and arm the Georgian military. It also helped Georgian troops return from Iraq after the Russian incursion into South Ossetia.
What is the status of South Ossetia?
South Ossetia has run its own affairs since fighting for independence from Georgia in 1991-92, in the aftermath of the collapse of the Soviet Union.
Like the other breakaway region, Abkhazia, it declared its independence - but so far only Russia and Nicaragua have recognised them.
Why do Ossetians want to break away?
The Ossetians are a distinct ethnic group originally from the Russian plains just south of the Don river. In the 13th Century, they were pushed southwards by Mongol invasions into the Caucasus mountains, settling along the border with Georgia.
South Ossetians want to join up with their ethnic brethren in North Ossetia, which is an autonomous republic within the Russian Federation.
Ethnic Georgians are a minority in South Ossetia, accounting for less than one-third of the population.
But Georgia rejects even the name South Ossetia, preferring to call it by the ancient name of Samachablo, or Tskhinvali, after its main city.
Are tensions over energy supplies a factor in the conflict?
A Western-sponsored pipeline has been pumping Caspian oil from Azerbaijan through Georgia to Turkey's Mediterranean coast. The Baku-Tbilisi-Ceyhan (BTC) pipeline can deliver up to 1.2 million barrels per day (b/d) of oil to Western markets.
But the flow has been suspended since an explosion on part of the line in eastern Turkey in August. The Georgia conflict has delayed a resumption of deliveries.
A smaller oil export pipeline runs from Azerbaijan to Georgia's Black Sea port of Supsa.
There are plans for another pipeline to take natural gas from Azerbaijan and Central Asia, via Turkey to Austria.
The EU and US are anxious to diversify their energy sources, to avoid being too dependent on supplies transiting through Russia. Moscow already controls an oil export pipeline running from the Caspian to the Black Sea via the North Caucasus.
Russian troops did not try to seize the BTC pipeline - and Moscow did not highlight energy as an issue in the conflict. But fears of instability in the Caucasus have made Western leaders and investors reassess their reliance on the region's energy sources.
How has the international community responded to the conflict?
The US has expressed solidarity and backing for Georgia, calling Russia's actions "an illegitimate, unilateral attempt to change the country's borders by force".
On a trip to Georgia, US Vice-President Dick Cheney said Russia's actions had cast "grave doubt" on the country's reliability as a partner within the international system.
Georgia's European neighbours have been somewhat more divided over how to react to the crisis at their heart. At an emergency summit in Brussels, some member states pushed for sanctions against Russia, seeking to isolate the country.
In the end, the EU condemned Russia's actions, called for it to meet the terms of the French-brokered ceasefire and suspended talks on a new partnership agreement with the bloc.
The US has pledged to provide a $1bn (£564m) aid package for reconstruction, resettlement and humanitarian needs. The IMF too has agreed in principle to give Georgia a $750m (£422m) loan to help repair the conflict's damage.
What are EU observers doing in Georgia?
The European Union has sent more than 200 observers to Georgia, in line with a 12 August ceasefire deal brokered by French President Nicolas Sarkozy. Their operation began on 1 October and their mission's initial duration is one year.
The unarmed observers, from 22 EU countries, are working in close co-ordination with the United Nations and the European security body, the OSCE.
One of their key tasks was to monitor the Russian troop withdrawal from "security zones" established by Russia around South Ossetia and Abkhazia.
Russia completed its troop pull-out as promised by 10 October, but it plans to keep nearly 8,000 troops in Abkhazia and South Ossetia.
Russia has refused to let the monitors enter the two breakaway regions.
The EU observers have the task of ensuring that the situation stabilises in the conflict zone, that human rights are not violated there and that internally displaced people can return home. Their liaison work is aimed at confidence-building and an easing of tensions.
How does the conflict mark a change in Russia's relations with the world?
Russian intervention in Georgia has been followed by an explicit shift in the country's foreign policy, laid out by the president. Mr Medvedev has pledged to continue to defend the lives and dignity of its citizens, wherever they are located.
He said that while Russia does not seek isolation, and desires friendly relations with Europe and the US, it cannot accept a world order that places a single state - even the US - as sole global decision-maker.
Russia, he said, seeks to maintain privileged interests in its spheres of influence - including those bordering the country.