2002
Mohammed Yusuf founds Boko Haram
He sets up a religious complex, which includes a mosque and an Islamic school. Many poor Muslim families from across Nigeria, as well as neighboring countries, enroll their children at the school.
The official Arabic name, Jama'atu Ahlis Sunna Lidda'awati wal-Jihad, means "People Committed to the Propagation of the Prophet's Teachings and Jihad"
It is nicknamed Boko Haram, a phrase in the local Hausa language meaning, "Western education is forbidden"
Boko Haram initially focuses on opposing any political or social activity associated with Western society - voting in elections, wearing shirts and trousers or receiving a secular education.
2009
Boko Haram launches military operations to create an Islamic state and attacks police stations and other government buildings in Maiduguri.
Boko Haram's trademark is originally the use of gunmen on motorbikes, killing police, politicians and anyone who criticizes it, including clerics from other Muslim traditions and Christian preachers.
It stages more audacious attacks in northern and central Nigeria, including bombing churches, buses, bars, military barracks and even the police and UN headquarters in the capital, Abuja.
This leads to shoot-outs on Maiduguri's streets.
Hundreds of Boko Haram supporters are killed and thousands of residents flee the city.
Nigeria's security forces eventually seize the group's headquarters, capture its fighters and kill Mr Yusuf. His body is shown on state television.
The security forces declare Boko Haram finished.
But its fighters regroup under a new leader, Abubakar Shekau.
2010
The USA designates it a terrorist organization, amid fears that it has links with other militant groups, such as al-Qaeda
2013
May 12
President Goodluck Jonathan declares a state of emergency in the three northern states where Boko Haram is the strongest - Borno, Yobe and Adamawa.
May 14
Boko Haram releases a video showing women and children hostage in response to the arrest of its members' wives and children. There is later a prison swap, with both sides releasing the women and children.
June through December
The group's fighters launch mass attacks on villages. They loot and burn properties in what appears to be a warning to rural people not to collaborate with the security forces.
2014
March
Boko Haram militants attack a boarding school in Yobe
April 15
They raid another school in Chibok and abduct more than 200 schoolgirls,
saying they will treat them as slaves and marry them off - a reference to an ancient Islamic belief that women captured in conflict are part of the "war booty".
April 16
The group's fighters continue with its urban bombing campaign. They target the capital and kill at least 70 people in an explosion near a car park.
May 2
19 people die in another urban bombing attack.
May 16
Boko Haram militants launch an attack in a Chinese workers' camp border region of neighboring Cameroon.
200 gunmen arrive in a convoy of vehicles in Waza and kidnap 10 Chinese engineers and kill one Cameroonian soldier,
May 17
The attack comes shortly before the start of Saturday's summit talks on Boko Haram in Paris, where five heads of state, including Nigerian President Goodluck Jonathan, meet to map out regional strategies to fight the militant group.
Representatives from the EU, Britain and other Western powers attend the meeting.
French President Francois Hollande says the Nigeria-based Boko Haram militant group is a threat to all of West and Central Africa and a "comprehensive plan" must be established to fight it.
