General, President of Congo-Brazzaville from 1979-1992, and from 1997 - present.
Just after the Congo's independence in 1960, Nguesso joined the army and, after training in Algeria and France became a member of the force's elite paratrooping squad.
He participated in the military coup in 1968 that brought Marien Ngoubai to power and was a member of the Parti Congolais du Travail founded the following year.
During Ngoubai's rule, Nguesso served on his cabinet, but when the President was assassinated, Nguesso played a large role in maintaining control until Colonel Joachim Yhombi-Opango took over.
In 1979, the Military Committee of the Party (Comite Militaire du Parti), of which he was briefly the head during the earlier coup, chose him as President.
The 1992 Presidential election saw three main players: Nguesso, Pascal Lissouba of the Pan-African Union for Social Democracy (UPADS), and Bernard Kolelas of the Congolese Movement for Democracy and Integral Development (MCDII). Nguesso was eliminated in the first round of elections and took leave in Paris.
He competed in the 1997 elections in which Lissouba and Kolelas were barred from campaigning. The fourth candidate, Andre Milongo, withdrew upon discovering the elections were rigged.
Having previously served as head of the Organization of African Unity from 1986-1987, Nguesso was nominated to the role of Chairperson of the African Union in 2006 in order to prevent the position from going to Sudanese President Omar al-Bashir.
Nguesso was born in the Oyo district in the northern part of the country. He is a member of the Mbochi ethnic group.
Nguesso's term of office is often linked to misuse of government money. In 2006 on two separate business trips, the President and his entourage ran up bills of over $140,000 in January, and over $200,000 in September - which the Sunday Times commented was "comfortably more than the £106,000 that Britain gave the Republic of Congo in humanitarian aid in 2006."
The British NGO Global Witness has also published reports of the President's son spending thousands of dollars from national oil profits on shopping sprees in Dubai and Paris.