Religion can have internal (esoteric) and external (exoteric) components. The esoteric approach is essentially mystical. The exoteric is essentially about adherence to the law. As institutions, churches are usually satisfied with the exoteric. Sometimes true believers want the esoteric in order to achieve union with God. In Islam, those who pursue the esoteric are often called “sufi.”
Nigeria gained its independence from Britain in 1956. The new nation divided between a Christian South, with access to rich oil resources, and a Muslim North, which suffered from poverty. Bitterness arose in the North, where people complained of both the evils of the Christian government and the failings of their own clergy and traditional leaders to obtain justice. A religious protest movement arose around Mohammed Marwa (c. 1920-1980, knick-named “Maitatsine”) that led to violence and deaths. The government never entirely managed to suppress support for it. Then, during the 1960s and 1970s, Sufism began to make in-roads among Muslims in northern Nigeria. Inspired by the Saudi Arabian Wahhabist-funded World Muslim League, Sheikh Ismaila Idris (1937-2000) began to push back. In 1978 he founded the Izala Society to advocate a traditional form of Islam. One of the bright lights of this movement was Ja’afar Mahmud Adam (1960-2007). He was trained as a teacher in Nigeria, then studied at the Islamic University in Saudi Arabia. From 1993 to 2007 he preached in a mosque in Kano, Nigeria. One of his followers was Mohammed Yusuf (1970–2009). About 2002, Adam and Yusuf fell out.
Yusuf went his own way to found Boko Haram. He seems to have recruited many of the same sorts of people with the same sorts of grievances who had followed Marwa twenty years before. Yusuf concentrated his mission on building support in the far northeast of Nigeria, near the borders with Chad and Niger. Yusuf may have aimed at the creation of an Islamist state. Certainly, he gathered arms and young men with nothing to lose. One of these was Abubakar Shekau. Shekau became Yusuf’s second-in-command.
In July 2009 Boko Haram clashed with Nigerian security forces and Yusuf was killed “while trying to escape.” Shekau took command of Boko Haram. In September 2010 he opened war against the government with a prison break that freed over a hundred members of the group. Beginning in 2011 Boko Haram has used bombings (suicide and IED) and shootings to drive the police off the street and then out of towns. As a result, general lawlessness spread throughout the north. The Army and police reacted violently, but usually against civilian target that came to hand rather than against the Boko Haram militants. Reports of massacres, rapes, and pillaging carried out by the “forces of order” became common. During 2013 the conflict spilled over into Chad, Niger, and Cameroon. In 2014, Boko Haram transiently caught the attention of the world when it kidnapped several hundred girls from a school at Chibok. The gory fight goes on.
As is the case in Syria and Iraq, the Islamists are up against corrupt or incompetent or non-existent governments. They aren’t fighting real soldiers: they’re fighting men with guns hired to prop up the government. They’re “filled with a terrible certainty,” while their opponents “lack all conviction.” Probably because the courts are rigged.
See: http://en.wikipedia.org/wiki/Boko_Haram for a more detailed account.
 In 2007 someone shot Adam to death in his mosque. The whole area was too violent to pin the blame on Yusuf.
 He may be anywhere from his mid-30s to his mid-40s.
 I haven’t seen a lot of “Bring back our girls” posts of late on my FB feed. First there was the “ice bucket challenge,” then all the memes sent out by groups like AddictingInfo to denounce the enormities of the Republicans.