Sometimes known under the aliases Gilbert Bourgeaud and Saïd Mustapha Mhadjou, he was known for having performed various jobs in support of Françafrique—France's sphere of influence in its former colonies in Africa—for Jacques Foccart, co-ordinator of President Charles de Gaulle's African policy.

Having served with the French Navy in the Algerian War, the ardently anti-communist Denard took part in the Katanga secession effort in the 1960s and subsequently operated in many African countries including Congo, Angola, Rhodesia (today Zimbabwe), and Gabon.

Denard had a swashbuckling, larger-than-life image as the South African journalist Al J Venter called him "a warrior king out of Homer" who achieved the dream of every mercenary by conquering the Comoros in 1978, which he ruled via a puppet president until 1989.

[9] In 1954, he was convicted of an assassination plot against Prime Minister Pierre Mendès-France, a left-wing member of the Radical-Socialist Party who was negotiating the end of the Indochina War and withdrawal from Morocco, Tunisia and Algeria, and served 14 months in prison.

[7] After about eighteen months Denard returned to the Congo to take employment under Moise Tshombe who was now the prime minister of the central government in Leopoldville from July 1964 till October 1965 when he was dismissed by President Joseph Kasa-Vubu.

Denard served for two years in the Congo battling Simba rebels supporters of the late Congolese leader Patrice Lumumba, who had been murdered in Katanga in 1961 after having been overthrown by rival politicians and severely tortured while in transit.

[15] Although Jacques Foccart denied knowledge of the attempted coup after its failure, he did recognize that it had been backed-up by Gnassingbé Eyadéma (Togo), Houphouet-Boigny (Ivory Coast), Omar Bongo (Gabon) and Hassan II (Morocco), all allies of France.

[citation needed] He then failed at a coup in Benin in 1977 and carried out some operations in Rhodesia from 1977 to 1978 as part of the Rhodesian Army's short-lived French-speaking unit, 7 Independent Company.

[7] With the support of the Rhodesian government,[16] he returned to the Comoros with 43 men on 13 May 1978 and carried out a coup against president Ali Soilih, who had turned toward socialist policies.

For eleven years (1978 to 1989),[7] Denard headed Abdallah's 500-strong presidential guard and had strong influence and business interests in the archipelago, marrying and converting to Islam and eventually becoming a citizen of the country.

[4] In 1989, fearing a probable coup d'état, president Ahmed Abdallah signed a decree ordering the Presidential Guard, led by Denard, to disarm the armed forces.

Denard landed on the Comoros with 33 men in Zodiac inflatable boats in an attempted coup against president Said Mohamed Djohar, Abdallah's successor.

Denard was brought back to France by the French DGSE intelligence agency [citation needed] and spent ten months in a Paris jail.

Dominique Malacrino talked about the "numerous phone calls of Jacques Foccart, then responsible for the African office at the Elysée palace" to Denard.

Emmanuel Pochet, another suspect, declared that Denard had "support from senior officers of the special forces of the DGSE", the French external intelligence agency.

[21] In June 2006 Denard, who by then was suffering from Alzheimer's, was found guilty of "belonging to a gang who conspired to commit a crime", and was given a five-year suspended jail term.

[22] During the trial, the role of the French secret services in the 1995 coup against Saïd Djohar was recognized, but not deemed sufficient to discharge the mercenaries of their guilt.