Tens of thousands of ethnic Armenians have fled from Nagorno-Karabakh since the territory surrendered to Azerbaijan on 20 September.
Local forces in Karabakh agreed to be disarmed and disbanded after an Azerbaijani military offensive triggered intense fighting.
The breakaway republic and its institutions will "cease to exist" from 1 January 2024, the region's separatist leader has said.
The territory is recognised internationally as part of Azerbaijan but large areas of it have been controlled by ethnic Armenians for three decades.
It is at the heart of one of the world's longest-running conflicts.
Where is Nagorno-Karabakh?
The territory lies in the mountainous South Caucasus region between the Black Sea and the Caspian Sea.
Azerbaijan and Armenia fought a bloody war over Nagorno-Karabakh in the late 1980s and early 1990s, and it has been the trigger for further violence in the years since.
Map of the Nagorno-Karabakh region in Azerbaijan, showing areas of the former autonomous region where Russian peacekeeping forces operate.
The map also highlights some of the cities in the area and the Lachin corridor, which, though not a part of the Nagorno-Karabakh region, is to remain under the control of Russian peacekeepers to act as a connection with Armenia for ethnic-Armenian population in the region.
Another map shows where Nagorno-Karabakh is located in the South Caucasus region of southeast Europe and Asia.
The last major escalation in the conflict took place in 2020 when thousands of people were reported killed in six weeks of fierce fighting.
The deployment of Russian peacekeepers brought the fighting to a halt at the time, but tensions had been ratcheting up for months ahead of the latest military operation.
What led to the latest fighting?
Fears of fresh violence rose when Azerbaijan mounted an effective blockade of a vital route into the enclave in December 2022.
The Lachin Corridor is the only road that connects the Republic of Armenia to Nagorno-Karabakh.
It is a key artery for supplies, and residents in the territory reported severe shortages of basic food items and medication during the blockade.
Azerbaijan accused Armenia of using the road to bring in military supplies, which Armenia denied. Baku also said it had offered food and aid several times via another road but Armenians in Nagorno-Karabakh refused it.
Maintaining access through the Lachin Corridor and another route, the Aghdam Road from Azerbaijan, relied heavily on the presence of Russian peacekeepers deployed in the area since 2020.
But Moscow's attention and military resources have been diverted by its invasion of Ukraine. The Armenian prime minister accused Russia of "spontaneously leaving the region".
Karabakh authorities said at least 200 people had died in the fighting, while Azerbaijan said that 192 of its soldiers had been killed.
Why are people fleeing ?
Azerbaijan and the ethnic-Armenians in Nagorno-Karabakh declared a ceasefire, mediated by Russia, on 20 September, which brought 24 hours of fighting to an end.
The agreement said local Armenian forces would be completely disarmed and disbanded.
Azerbaijan and the Karabakh authorities have since started talks about the integration of the enclave into Azerbaijan.
But the territory's separatist leader, Samvel Shahramanyan, also signed an order dissolving all state institutions from next year, effectively ending the territory's struggle for independence.
Mr Shahramanyan said the decision to dissolve the state was "based on the priority of ensuring the physical security and vital interests of the people", referencing Azerbaijan's agreement that "free, voluntary and unhindered travel is ensured to residents".
Armenia said more than half of the estimated 120,000 ethnic Armenians fled the territory in the week after the ceasefire, fearing they would have no future in Nagorno-Karabakh.
The Lachin Corridor was packed with hundreds of buses and cars of people trying to leave.
Armenia's Prime Minister Nikol Pashinyan has said he expects there will be no Armenians left in Nagorno-Karabakh in the near future.
Azerbaijan has said it wants to integrate the region's population as "equal citizens" and dismissed allegations of ethnic cleansing levelled by Armenia.
The country's president, Ilham Aliyev, also said that Azerbaijanis who were displaced from the region in the decades-long conflict should have the option of returning.
The two countries have never signed a peace deal and despite negotiations over the years do not have formal diplomatic relations.
What led to war?
Modern-day Armenia and Azerbaijan became part of the Soviet Union in the 1920s.
The area designated Nagorno-Karabakh had a majority ethnic-Armenian population but was controlled by Azerbaijan.
Nagorno-Karabakh's regional parliament voted to become part of Armenia when the Soviet Union began to collapse in the late 1980s.
Azerbaijan sought to suppress the separatist movement, while Armenia backed it.
This led to ethnic clashes and - after Armenia and Azerbaijan declared independence from Moscow - a full-scale war.
Years of bloodshed and suffering followed.
BBC Azerbaijani Service editor Konul Khalilova remembers how hundreds of thousands of ethnic Azerbaijanis were forced out of Armenia, becoming refugees in Azerbaijan.
In February 1992, residents of the Azerbaijani town Khojaly, situated in the Nagorno-Karabakh area, were killed by Armenian forces, helped by some of the Russian military. More than 600 people died, according to Azerbaijan. Armenia disputes the account and the number of deaths.
Over the years, tens of thousands of people were killed and more than a million displaced amid reports of ethnic cleansing and massacres committed by both sides.
Khalilova says it sometimes surprises her how little young people in both countries know about the atrocities.
No-one tells Armenians about the Azerbaijanis who were killed; likewise, young Azerbaijanis today do not hear about pogroms of the Armenian people in Azerbaijani cities such as Sumgayit and Baku at the end of the 1980s, she says.
Azerbaijan disputes the accounts of pogroms.
The first Nagorno-Karabakh war ended with a Russian-brokered ceasefire in 1994, after Armenian forces had gained control of Nagorno-Karabakh and areas adjacent to it.
Under the deal, Nagorno-Karabakh remained part of Azerbaijan, but since then it has mostly been governed by a separatist, self-declared republic, run by ethnic Armenians and backed by the Armenian government.
What happened in 2020?
The situation has been volatile ever since, with bouts of fighting interrupting periods of relative calm.
The biggest military confrontation since the early 1990s happened three years ago during six weeks of heavy fighting.
Azerbaijan won back territory and by the time both sides agreed to sign a Russian-brokered peace deal in November 2020, it had recaptured all the territories surrounding Nagorno-Karabakh held by Armenia since 1994.
Under the agreement, Armenian forces had to withdraw from these areas and have since been confined to a smaller part of the region.
A woman visits the grave of a soldier killed during the Nagorno-Karabakh conflict of 2020.
Who do Russia and Turkey support?
Regional powers have been heavily involved in the conflict over the years.
Turkey has close cultural and historical links to Azerbaijan. Turkish-made Bayraktar drones are said to have played a crucial role in the fighting in 2020, allowing Azerbaijan to make territorial gains.
Armenia, on the other hand, traditionally had good relations with Russia. There is a Russian military base in Armenia, and both are members of the Collective Security Treaty Organization (CSTO) military alliance of six former Soviet states.
But relations between Armenia and Russia have soured since Nikol Pashinyan, who led huge anti-government protests in 2018, became Armenia's prime minister.
He recently said Armenia's reliance on Russia as its single source for security was a "strategic error". Armenia held joint exercises with US forces earlier this month.
Following the fighting in Nagorno-Karabakh, Mr Pashinyan criticised the role Russian peacekeepers had played and publicly questioned whether remaining a CSTO member was in Armenia's interest.
Russia has rejected Mr Pashinyan's comments as "unacceptable outbursts addressed against Russia [that] can spark nothing but rejection".
"The leadership in Yerevan is making a big mistake by deliberately trying to destroy Armenia's multifaceted and centuries-old ties with Russia, and by holding the country hostage to the geopolitical games of the West," Russia's foreign ministry said.
The Kremlin has also criticised "extremely hostile" moves by Armenia to join the International Criminal Court (ICC), which has issued an arrest warrant for President Vladimir Putin.