It was established on 19 September 1967 during the Nigerian Civil War as a puppet state of Biafra, following its occupation of Nigeria's Mid-Western Region, and named after its capital, Benin City, with Albert Nwazu Okonkwo as its head of government.

In the lead-up to the Nigerian Civil War, residents of the ethnically diverse Mid-Western Region attempted to take a neutral position.

However, the mass media campaign began to fill the state with news about the oppression of the Igbo in Nigeria, and as the days passed, only increased the region's ethnic divide.

[1]: 377  As relations between the occupational government and non-Igbos continued to deteriorate, Biafran President C. Odumegwu Ojukwu visited the Mid-Western Region to raise support and met with leaders of the previously banned National Convention of Nigerian Citizens (NCNC).

On 19 September 1967, the Biafrans rebranded the region by proclaiming the Republic of Benin, an independent state separate from Biafra, as a last-ditch effort.