President Denis Sassou-Nguesso of Congo, named chairman of the African Union at its summit meeting in Khartoum , is a career soldier who has never been afraid to use force to further his political ambitions.
Sassou-Nguesso returned to Congo in 1997 after a three-year exile in Paris and seized power in an armed uprising, becoming president for the second time and replacing the man, Pascal Lissouba, who had ended his 13-year Marxist-Leninist rule in 1992.
He was confirmed as president in highly contested elections in 2002.
As both head of state and head of the government, Nguesso has ruled over his impoverished nation of three million people by facing down challenges from rebel groups and accusations of corruption and mismanagement of resources, especially the state-run oil sector upon which Congo heavily depends.
Sassou-Nguesso, 63, an ethnic Mboshi, was born in the northern village of Edou in 1943 and joined the army in 1961, the starting point of his increasing important role in the violent and troubled history of his country.
A committed Marxist, Sassou-Nguesso played a leading role in the uprising that brought down president Fulbert Youlou's government in August 1963.
The following year he graduated as a lieutenant from officer school in France, the former colonial power with whom he has always been at pains to maintain close ties.
In 1968, he took part in the military coup that swept Major Marien Ngouabi to power and was rewarded with the post of director of state security and later defence minister.
He co-founded the Congolese Labour Party (PCT), Africa's first Marxist-Leninist party, in 1969. And after Ngouabi's assassination in 1977 he led an opposition movement within the PCT that deposed party leader and Congolese president Joachim Yhombi-Opango in 1979.
Sassou-Nguesso took over as head of state and ruled for 13 years until the spirit of democratisation sweeping through Africa produced a national referendum that ushered in multi-party politics in 1992. He was defeated in the subsequent presidential elections by Lissouba.
Sassou-Nguesso's first presidency was marked by a determined pragmatism which saw an ambitious regional development plan come to fruition in the early 1980s. In three years alone, more than 1,000 kilometres (600 miles) of roads and bridges were built, providing the country with a thoroughly modern road network.
On an international level, too, Sassou-Nguesso was a key player in Africa at the time. His close links with the Cuban-backed Angolan government allowed him to act as potential peace broker, even down to inviting representatives of the Luanda regime and the apartheid government of South Africa, who supported Angola's UNITA rebel movement, to Brazzaville for talks in 1988.
His standing in the region was further enhanced when his daughter Edith became the second wife of Gabonese president Omar Bongo in January 1990, making him father-in-law to the longest serving head of state in central Africa, a man seven years his senior.
After his electoral defeat in 1992, Sassou-Nguesso disappeared into the political wilderness while three separate civil wars ravaged his country in the space of a few years.
But in 1997, when the latest war had been raging for five months, he re-emerged as head of the opposition United Democratic Forces, a coalition of six parties including the PCT. With the help of his Angolan allies, Sassou-Nguesso ousted Lissouba and proclaimed himself head of state once more.
But his return did not bring peace and at the end of 1998 violence erupted afresh, leaving thousands dead before a formal ceasefire could be signed at the end of 1999.
Sassou-Nguesso continued in office unchallenged and his position was reinforced in September 2001 when parliament approved a new constitution that handed wide-ranging powers to the president.
That constitution was heavily endorsed by a referendum in January 2002 that paved the way for highly contested elections two months later in which most opposition candidates either pulled out or were excluded.