Alias Gilbert Bourgeaud, alias Said Mustapha Mahdjou, he was born on 7 April 1929, in Bordeaux. His connection with the Comoros islands goes back at 20 years, when he helped Ali Soilih to power. He fell out with the new president, turning his attention to the west African state of Benin and an abortive coup there, before returning to the Comoros where he engineered the overthrow of his former protege and installed Ahmed Abdallah as a puppet president in 1978.
Denard, who has Comorian citizenship, was technically commander of the Presidential Guard but to all intents and purposes was regent of the country until Ahmed Abdallah died in obscure circumstances in 1989. Denard was widely reported to have been implicated in Abdallah's death.
He was then evicted by French troops and went to South Africa before returning to France in 1993 where he was convicted in April of that year for his role in the Benin coup and given a five-year suspended sentence. But at his trial a series of more or less shadowy figures from the intelligence services made it plain that Denard's buccaneering mercenary career had, on some occasions, the blessing of the French state.
It was suggested that the relatively light sentence might have been a trade-off for Denard's silence on certain sensitive issues, but the man himself said nothing.
He founded a security firm and seemed to be doing well, trading on his African contacts. He is still under investigation for his role in the death of Abdallah in 1989.