Mokhtar Belmokhtar, the one-eyed Islamist who masterminded a brazen attack on an Algerian gas field, was branded "the Uncatchable" - but the desert fox has now reportedly been killed in northern Mali.
The death of one of the world's most wanted jihadists would be a major blow to al-Qaeda in the region and to Islamist rebels already forced to flee towns they had seized in northern Mali by an offensive by French and African troops.
"On Saturday, March 2, at noon, Chadian armed forces operating in northern Mali completely destroyed a terrorist base. ... The toll included several dead terrorists, including their leader Mokhtar Belmokhtar," Chad's armed forces said in a statement read on national television.
On Friday, Chad's president, Idriss Deby, said his soldiers had killed another al-Qaeda commander, Adelhamid Abou Zeid, among 40 militants who died in an operation in the same area as Saturday's assault - Mali's Adrar des Ifoghas mountains near the Algerian border.
France - which has used jet strikes against the militants' mountain hideouts - has declined to confirm the killing of either Abou Zeid or Belmokhtar.
In Washington, an Obama administration said the White House could not confirm the killing of Belmokhtar.
"Both men have extensive knowledge of northern Mali and parts of the broader Sahel and deep social and other connections in northern Mali, and the death of both in a short amount of time will likely have an impact on militant operations," said Andrew Lebovich, a Dakar-based analyst who follows al-Qaeda in the Islamic Maghreb (AQIM).
Anne Giudicelli, managing director of security consultancy Terrorisc, said the al-Qaeda commanders' deaths - if confirmed - would also raise concern over the fate of seven French hostages believed to be held by Islamists in northern Mali.
Chad is one of several African nations that have contributed forces to a French-led military intervention in Mali aimed at ridding its vast northern desert of Islamist rebels who seized the area nearly a year ago following a coup in the capital.
Western and African countries worry that al-Qaeda could use the zone to launch international attacks and strengthen ties with African Islamist groups such as al-Shabab in Somalia and Boko Haram in Nigeria.
Belmokhtar, 40, who lost an eye while fighting in Afghanistan in the 1990s, claimed responsibility for the seizure of dozens of foreign hostages at the In Amenas gas plant in Algeria in January in which more than 60 people died.
That attack put Algeria back on the map of global jihad, 20 years after its civil war, a bloody Islamist struggle for power. It also burnished Belmokhtar's jihadi credentials by showing that al-Qaeda remained a threat despite US forces killing Osama bin Laden in Pakistan in 2011.
Before In Amenas, some intelligence experts had assumed Algerian-born Belmokhtar had drifted away from jihad in favour of kidnapping and smuggling weapons and cigarettes in the Sahara where he earned the nickname "Marlboro Man".
In a rare interview with a Mauritanian news service in late 2011, Belmokhtar paid homage to bin Laden and his successor, Ayman al-Zawahiri. He cited al-Qaeda's traditional global preoccupations, including Iraq, Afghanistan and the fate of the Palestinians, and stressed the need to "attack Western and Jewish economic and military interests".
He shared command of field operations for AQIM - al-Qaeda's North African franchise - with Abou Zeid, although there was talk the two did not get along and were competing for power.
A former smuggler, Algerian-born Abou Zeid imposed a violent form of Islamic law in the ancient town of Timbuktu, including amputations and the destruction of ancient Sufi shrines.
Robert Fowler, a former Canadian diplomat held hostage by Belmokhtar from 2008 to 2009, said: "While I cannot consider reports of the death of both Abou Zeid and Mokhtar Belmokhtar as anything but good news ... I must temper my enthusiasm by the fact that this is by no means the first time Belmokhtar's death has been reported."
Reuters, Agence France-Presse