It's been three years since the kidnapping of 276 schoolgirls from Chibok in northern Nigeria. Boko Haram continues to be at the forefront of a nine year-long insurgency, creating one of the biggest humanitarian crises in the world.
At its founding in 2002, the Boko Haram sect initially sought to preach Islam and help educate the impoverished youth of north-east Nigeria.
But far from these roots of helping the impoverished, the internationally recognised terrorist group is severely affecting millions of people in Nigeria, Chad, Niger and Cameroon.
The conflict has led to more than 20,000 deaths and displaced 2.4 million people and there no end in sight after almost a decade of bloodletting, vengeance and militancy.
Here's a brief timeline of key moments in the history of the Boko Haram crisis: