Algeria gave birth to most of the hardened Islamist militants who over the past two decades have created the well-armed North African extremist movements that are fighting France from desert redoubts in Mali and took the Western hostages at an Algerian gas production site near Libya.

Mokhtar Belmokhtar, 40, the one-eyed chieftain whose gunmen captured the American and other hostages Wednesday, is a prime example. Born in Algeria in 1972, he departed for combat in Afghanistan while still a teenager and returned two years later, having lost his left eye and earning the nickname “one-eye.”

As soon as he set foot on Algerian soil again, in 1993, Belmokhtar joined the Armed Islamic Groups, an extremist underground group fighting the army-dominated Algerian government and seeking to impose strict Islamic rule. Along with two other main groups, the Islamic Salvation Army and the Salafist Group for Preaching and Combat, he and his comrades in arms battled in a merciless guerrilla war in the Algerian backlands until 2002.

The war had begun in 1991 when the Algerian army canceled parliamentary elections after it looked like an Islamist party, the Islamic Salvation Front, was about to gain a majority. The army’s move forced President Chadli Benjedid to resign and end his experiment with democracy, leaving the army in full charge and sparking the civil war.

Defeated by the Algerian army a decade later, Belmokhtar and most of his fellow guerrilla fighters scattered to the thinly populated mountains along the border between Algeria and Mali, and roamed the desert-like flatlands across northern Mali, Mauritania and Niger.

It was there that al-Qaeda in the Islamic Maghreb (AQIM) took shape, in the form of three divisions of fighters with separate leadership but all dedicated to hostage-taking, smuggling and propagation of strict Islamic ways. The Algerian-formed divisions over the years began attracting recruits from other countries as well, such as Mali, Mauritania and even Pakistan.

Belmokhtar was the leader of one of the columns, but he was often dismissed by Algerian and French security officials as more interested in cigarette smuggling and ransom than in Islamic probity. Reflecting their disdain, Algerian security agents gave him a new nickname: “Mr. Marlboro.”

More seriously, Belmokhtar was involved in a half-dozen hostage takings over the past decade and reportedly amassed a fortune in ransom payments from governments and multinational companies negotiating through intermediaries, often including Malian military intelligence officers. Along with his fellow guerrillas, Belmokhtar improved his group’s armament with weapons carted in from Libyan strongman Moammar Gaddafi, who was booted from power in 2011 by rebels backed by Western air power.

The overall AQIM leader, however, remained Abdelmalik Droukdel. Another veteran of the 1990s Algerian civil war, he remained in a northern Algeria hideout, from which his forces still mount occasional attacks on Algerian government or military installations.

Droukdel negotiated the accord that in 2006 resulted in the North African groups’ absorption into Osama bin Laden’s al-Qaeda. Only after prolonged ideological and theological debates, often carried out on Internet sites, did they take the name al-Qaeda in the Islamic Maghreb, according to Mathieu Guidere, professor of Islamic studies at Toulouse University and a well known specialist on North African extremist groups.

Belmokhtar broke with AQMI last month, according to Guidere and other specialists, and formed his own group called “Signatories in Blood.” That was the name he used Wednesday in announcing his takeover of the gas plant. Although the reason for the break remained unclear, Belmokhtar’s gunmen had clashed in the northern Mali city of Gao in June with an allied secular group of Malian Tuaregs, the Azawad National Liberation Front.