The Lagos Conference of African States, 25–30 January 1962, was the most ambitious diplomatic event Nigeria had hosted since the 1957 Constitutional Conference. Sir Abubakar Tafawa Balewa convened twenty heads of state and government — including Emperor Haile Selassie I of Ethiopia, President William Tubman of Liberia, President Sylvanus Olympio of Togo, President Hamani Diori of Niger, and President Maurice Yaméogo of Upper Volta — to forge a continental moderate alliance in opposition to the Casablanca Group of Nkrumah, Nasser and Sékou Touré.
The Emperor's address on 26 January 1962, delivered at the House of Representatives in Lagos, framed African unity as a 'sacred duty' and a 'historical necessity'. Selassie was already, at sixty-nine, the longest-serving head of state on the continent; his presence in Lagos legitimised Balewa's Monrovia Group framework. Sixteen months later, on 25 May 1963, those same governments would meet again in Addis Ababa under Selassie's chairmanship to sign the Charter of the Organisation of African Unity — and the Lagos Conference is now generally treated as the OAU's effective foundation moment. Selassie travelled with a forty-strong delegation, was received at Ikeja by Governor-General Nnamdi Azikiwe and by Balewa, and was lodged at State House, Marina.