Africa's Great Lakes, but bad neighbours
The Great Lakes region of Africa is renowned for its beauty, with rolling green volcanic hills surrounding vast lakes, but it is also infamous for being the continent's most unstable area.
Millions of people have been killed in conflict since the end of colonial rule and neighbourly relationships between the countries surrounding the lakes have often been treacherous.
As African leaders meet in Kenya to discuss the ongoing unrest in the region, BBC Africa's Farouk Chothia looks at why the Democratic Republic Congo, Rwanda, Uganda, Tanzania and Burundi have often made such bad neighbours and why the summit may prove a diplomatic nightmare:
Geographically, it is the biggest country in sub-Saharan Africa, located in the heart of the continent. It is also rich in resources - gold, diamonds, cassiterite and coltan, used in mobile phones.
Its enormous wealth attracts many foreign powers and groups, all of whom have contributed to its instability. Although DR Congo is rich in mineral resources, its population is poorer than that of neighbouring states, and it has the largest number of armed groups in Africa, more than 20.
The country has been marred in conflict since independence from Belgium in 1960. It was at the centre of what could be termed Africa's world war - a five-year-long conflict in which millions died between 1998 and 2003. The conflict drew in at least five countries - Angola, Namibia and Zimbabwe, which sent troops to back President Joseph Kabila, and Rwanda and Uganda, which sent troops to support rival rebel groups. Elite Angolan forces are among the bodyguards who protect President Joseph Kabila, showing the extent to which he is dependent on outside help for his survival.
Currently, he is facing his biggest threat from the M23 rebel group, which briefly seized the regional capital, Goma, last year. An estimated 800,000 people have fled their homes since it launched its rebellion in April 2012.
The M23 is made up mostly of people from the Tutsi ethnic group, which explains the Rwandan government's support for it, analysts say. They feel marginalised by the government in faraway Kinshasa, and are demanding a better deal for DR Congo's Tutsis.
Its minerals have been smuggled throughout the region, causing a diplomatic incident between DR Congo and Kenya two years ago when it was discovered that Nairobi was at the centre of multi-million dollar smuggling ring.
Often described as the little bone which sticks in the throat, Rwanda is a power-broker in the region largely because of the support it has commanded in the US and UK.
Carrying the guilt of failing to intervene to stop the 1994 genocide that killed some 800,000 people, the US and UK have since spent millions of dollars to help Rwanda recover.
The government which took power after the genocide is dominated by Tutsis, even though the majority of Rwandans are Hutus.
It sees the the Democratic Liberation Forces of Rwanda (FDLR), a Hutu rebel group, as a major threat to its stability - and crossed the border into DR Congo on several occasions to confront them.
The founders of the FDLR fled to eastern DR Congo after the genocide, causing Rwanda to fear that it would use it as a base to fight President Paul Kagame's rule.
This is the main reason why Rwanda's government has kept a military interest in the region, backing groups that can act as a buffer between it and the FDLR.
Uganda was a refugee and military base for Rwandan Tutsis before they seized power in Kigali in 1994. Mr Kagame helped his Ugandan counterpart Yoweri Museveni, then a rebel leader, capture power in Kampala in 1986.
Mr Museveni returned the favour by helping Mr Kagame install himself as Rwanda's president eight years later - partly as a result, English was adopted as an official language in French-speaking Rwanda.
The two leaders later sent troops to DR Congo, helping then-rebel leader Laurent Kabila capture power in Kinshasa in 1997.
Their relationship then soured, as Uganda and Rwanda fought for the spoils of power in resource-rich eastern DR Congo. But the two leaders rebuilt relations, following diplomatic pressure from the UK and US.
Last year, Mr Kagame spent his Christmas holiday in Uganda - something he would not have done if relations were strained, analysts say.
Mr Museveni's government has been battling the Lord's Resistance Army (LRA) rebel group, which has now taken refuge in the Central African Republic (CAR) after being driven out of northern Uganda.
US special forces helped Uganda's military to pursue the rebels, but the operation was called off after CAR's president was overthrown in March. The LRA has roamed across the region - it was once even based in lawless eastern DR Congo, giving Uganda a pretext to remain involved in the country.
Leading the most peaceful and democratic country in the region, Tanzania's President Jakaya Kikwete raised eyebrows on 25 July when he warned that "anyone who dares invade or provoke us will face dire consequences".
His comments were seen as a warning to Rwanda, following a rise in diplomatic tension between the two countries. It started in May when Mr Kikwete told the Rwandan and Ugandan governments to enter into talks with the respective rebel groups battling them, the FDLR and Allied Democratic Forces (ADF).
Rwanda's President Kagame dismissed his advice as "utter nonsense". For his part, Mr Museveni said he only negotiates with those "willing and isolates the others".
Mr Museveni and Mr Kagame excluded Mr Kikwete last month from talks to promote political and regional integration, fuelling speculation that tension between them had heightened.
Tanzania is the region's most peaceful and democratic country, but it fought a war with Uganda in the late 1970s - ousting Idi Amin - after accusing it of backing rebels on its territory.
Now, many Tanzanians are worried that Rwanda could threaten their stability, by creating a rebel force on its territory in response to their government's policy on DR Congo, analysts say.
Some 1,800 Tanzanian troops are part of the 3,000-strong UN brigade deployed in eastern DR Congo earlier this year with a mandate to disarm rebel groups, especially the M23, widely suspected to be backed by Rwanda. Tanzania's decision to contribute to the force is the main source of tension with Rwanda, analysts say.
Economically the weakest country in the region, Burundi has little diplomatic clout among its neighbours.
Led by Pierre Nkurunziza, a former rebel leader from the Hutu ethnic group, it currently has fairly good relations with all its neighbours, including Rwanda, where the government is dominated by the rival Tutsi ethnic group.
Mr Nkurunziza's strongest regional ally is Tanzania, which hosted peace talks to end the Hutu-Tutsi conflict that killed about 300,000 people in Burundi between 1994 and 2005.
The peace accord led to Tutsi domination ending in Burundi, where the majority of people are Hutus, with an agreement that posts in the government and army be proportionately divided among ethnic groups.
In 1972, some 200,000 people were killed in what some analysts describe as the first mass slaughter in the region in the post-independence era.
The then Tutsi-led army was accused of unleashing violence against a Hutu insurgency, forcing hundreds of thousands of Hutus to become refugees in Tanzania, most of whom have since returned.