2009 Boko Haram launches its military campaign for Islamist rule.
July 2009 Hundreds die in Maiduguri, in north-eastern Borno state, when members set several churches, a police station and a prison on fire.
Police are among the victims of attacks by motorcycle-riding gunmen in northern Nigeria. The uprising is eventually crushed by a police and military assault, with hundreds dead and the sect's headquarters and mosque left in ruins. Boko Haram's leader, Mohammed Yusuf, is captured by the army and passed to police for interrogation. He dies in custody.
September 2010 The group frees 721 prisoners, including 105 suspected sect members, from a Bauchi jail in northern Nigeria. The violence coincides with the runup to the presidential elections.
December 2010 Boko Haram regroups under a new leader, Abubakar Shekau, and bombs Jos, in central Nigeria, killing 80 people. It is also blamed for a New Year's Eve attack on Abuja barracks. The incidents mark the beginning of a killing spree, with the group targeting its critics.
June 2011 Police headquarters are bombed in Abuja, killing six people. United Nations headquarters in the capital are targeted just two months later, destroying the lower floor of the building. Eighteen people are killed and dozens injured.
November 2011 The motorcade of the Borno state governor, Kashim Shettima, comes under bomb attack in Maiduguri as he returns from a trip abroad. About 150 die in co-ordinated bombing and shooting attacks on police facilities in Damaturu and Potiskum in Yobe state.
Two suicide bombers blow themselves up outside military headquarters in Maiduguri in what was described as a botched attack.
December 2011 Multiple bomb attacks on Christmas Day kill dozens, including 35 at St Theresa's church in Madalla, near the capital. A second explosion shortly afterwards hit a church in the central city of Jos, where a police officer was killed by gunfire. Three attacks in northern Yobe state kill four people. Two further attacks hit the town of Damaturu, and a third strikes Gadaka.
January 2012 Bombing kills at least 180 people in Kano, the deadliest attack to date.
June 2012 Offices of ThisDay newspaper are bombed. Later in the month, more than 100 people die in attacks on three churches in Kaduna, a city on the border of the Muslim north and the predominantly Christian south.
September 2012 The group attacks mobile phone masts belonging to nine telecommunications companies.
The army announces it has killed at least 35 suspected members of Boko Haram.
