Abubakar Shekau (; 1969 or 1975 – 20 May 2021), also known by his alias Darul Tawheed, is a Nigerian Islamist terrorist. He is the leader of the Nigerian militant group Boko Haram, whose insurgency began in 2009. He served as deputy leader to the group's founder, Mohammed Yusuf, until Yusuf was killed in 2009. Shekau then became the leader of the group.