Western Region of Nigeria
The Western Region of Nigeria was established as one of three regions united in the Federation of Nigeria as laid out in the Lyttleton constitution adopted in 1954. On creation, it was the second largest and least ethnically diverse (most homogeneous) of Nigeria's three regions, with an overwhelming Yoruba ethnic majority of around 75%. It had Eight provinces, two of which were mostly occupied by ethnic minorities. Its capital was in the city of Ibadan.
On August 9 1963, the ethnic minorities of the Western region comprising around some 20% of the regional population resident in the Benin and Warri Provinces were all-together carved out to create the new Mid-Western Region with its capital at Benin City, leaving the successor "New Western" region nearly ethnically homogeneous at over 95% Yoruba even with the immigrant non native groups in its various urban clusters taken into account. According to the national census of 1963, the 'New West' had a population of 10,265,846 people, while the Mid-West had a population of 2,535,839 people.
Four years later, on 27 May 1967, the "New Western region" was subdivided into Western State and Lagos State.