events
August 6, 1861
Britain imposes the Lagos Treaty of Cession to suppress slavery in what is now Nigeria.
Lagos Treaty of Cession
The Treaty of Cession, 6 August 1861 or the Lagos Treaty of Cession was a treaty between the British Empire and Oba Dosunmu of Lagos wherein Dosunmu, under the threat of military bombardment, ceded Lagos Island to Britain, whilst retaining the title and powers of Oba, subject to English laws.