Following is a timeline of events since the Boko Haram jihadist group abducted more than 200 schoolgirls in the remote town of Chibok in north-eastern Nigeria in 2014.
SNATCHED FROM SCHOOL
On April 14, 2014, Boko Haram gunmen seize 276 girls from the Government Girls Secondary School in Chibok, Borno state.
The girls are forced from their dormitories onto trucks and driven into the bush. Fifty-seven girls manage to flee.
Boko Haram leader Abubakar Shekau claims responsibility in a video released on May 5, and vows to sell the girls as slave brides.
A week later, a second video shows about 100 of the missing girls. Boko Haram says they have converted to Islam and will not be released unless militant fighters held in custody are freed.
An international media campaign is launched, backed by US First Lady Michelle Obama and Nobel Peace Prize laureate Malala Yousafzai. The hashtag #BringBackOurGirls fires up a social media storm.
On May 17, Benin, Cameroon, Chad, Niger and Nigeria vow to fight Boko Haram together, in what Cameroon President Paul Biya terms a "declaration of war".
The UN Security Council says the kidnappings "may amount to crimes against humanity", as Britain, China, France, Israel and the US offer help.
US military specialists deploy to neighbouring Chad but later move elsewhere after Nigeria stops requesting their services.
On May 26, Nigeria's Chief of Defence Staff Alex Badeh says the girls have been located but warns a rescue operation would put their lives at risk.
ONE YEAR ON
On April 14, 2015, Nigeria's president-elect Muhammadu Buhari warns he "cannot promise that we can find" the girls, as vigils are held in many countries to mark their first year in captivity.
Amnesty International says the girls may have been separated into three or four groups and are being held in camps, some of which might be in Cameroon or Chad.