April 2014: Boko Haram extremists kidnap 276 schoolgirls from Chibok in northern Nigeria, the region where the insurgency emerged several years ago.
November 2014: Extremists seize Chibok, and Nigerian army takes back the town.
May 2015: New President Muhammadu Buhari is sworn in, pledging to tackle Boko Haram “head-on.”
April 13, 2016: Boko Haram video appears to show some of the Chibok girls, and tearful mothers recognize their daughters.
May 18, 2016: Relative says one of the Chibok girls is found, pregnant, in a forest; pressure grows on Nigeria’s government to rescue the others.
Aug. 14, 2016: Boko Haram video says some Chibok girls are killed in airstrikes and demands release of extremists in exchange for the other girls’ freedom.
Oct. 13, 2016: Spokesman for Nigeria’s president confirms 21 Chibok girls have been freed, a result of government negotiations with Boko Haram. Nigeria’s government says another 83 girls would be released “very soon.”
Nov. 5, 2016: Military announces the first army rescue of a Chibok girl, during a raid on a forest hideout.
Dec. 24, 2016: Nigeria’s president declares that Boko Haram has been crushed, driven from its last forest hideout.
Jan. 5, 2017: Nigeria’s army says soldiers find one of the schoolgirls wandering in the bush near the forest stronghold.
April 14, 2017: Nigerians mark three years since the mass abduction.
May 6, 2017: Nigerian official says another group of schoolgirls is released.