The Aba Women's War is the earliest major documented crisis in Nigeria's modern accountability record and, by most accounts, the largest anti-colonial uprising in West Africa during the interwar period. Its roots lay in the colonial "warrant chief" system, introduced by the British as an administrative shortcut that imposed individuals with powers of tax collection and local enforcement they had not traditionally held. The immediate trigger came in late 1929 when colonial officials began a census widely understood — correctly, as it turned out — as a precursor to extending direct taxation to women, who had previously been exempt. Rumours spread that officials were counting women's livestock, children and household goods as taxable property.
Beginning in November 1929, an estimated two million women across roughly 6,000 square miles mobilised within weeks, without male leadership and without any modern communications infrastructure — using the traditional Igbo protest method known as "sitting on a man" (ogu umunwanyi). Protesters attacked warrant chiefs' compounds, colonial Native Court buildings, and European trading factories, destroying records and property associated with the system they were protesting. The protests spread across present-day Abia, Imo, Akwa Ibom and neighbouring areas.
The colonial response was lethal: police, and in some accounts troops, opened fire at Opobo, Utu Etim Ekpo and Abak, killing more than fifty women — a figure confirmed by the Aba Commission of Inquiry convened in 1930. No colonial police or soldier was prosecuted. The Commission did force the colonial government to acknowledge serious flaws in the warrant chief system, leading to reforms intended to make local authority structures more responsive — though the underlying system was not fully dismantled for some years. The pattern of colonial overreach, mass mobilisation, lethal state response and an inquiry that documents but does not fully remedy would recur, in various forms, throughout the next ninety-five years of Nigerian history.