Colonial era (1900–1959) — Enugu State

Aro-Ibibio Expedition (1 Dec 1901 – 24 Mar 1902) — Lt-Col. Festing's 1,500-man column dynamited the Long Juju at Arochukwu on 28 December 1901. The Aro diaspora houses at Ndi-Aro Nsukka and Ndi-Aro Eha-Alumona — inland nodes of the cowrie-credit network — were dismantled. See How the currency fell before the flag.
Ekumeku spillover (1902–1909) — the western-Igbo Ekumeku secret-society resistance against the RNC and the early Southern Nigeria Regiment spilled into Oji River and Awgu LGAs.
Ngwo land-seizure for the colliery (1914–1915) — the colonial state expropriated Ngwo ancestral land at Iva Valley, Ogbete and Onyeama for the new Government Colliery. Compensation was paid in sterling at colonial valuations; no traditional ruler signed under indigenous consent procedures. The dispossession is the origin of the modern Enugu housing question.Impunity Loop
Onyeama disturbances (1925) — first major colliery strike under the Northern Rhodesian copper-belt model wage-system; suppressed without fatalities.
★ IVA VALLEY MASSACRE — 18 NOVEMBER 1949 ★ — colonial police under Captain F.S. Phillips (Assistant Superintendent, Enugu) opened fire on 800 striking coal miners at Iva Valley demanding withheld 'rost money' (danger-pay arrears). 21 miners killed, 51 wounded. The Fitzgerald Commission of Enquiry (May 1950) indicted Phillips personally and found the police use of force "without justification". No officer was prosecuted. The massacre catalysed the Zikist Movement (Mokwugo Okoye, M.C.K. Ajuluchukwu, Raji Abdallah) into mass civil-disobedience, accelerated the Macpherson Constitution timetable, and made Enugu the symbolic capital of Nigerian labour radicalism. See The Iva Valley Coal Miners' Massacre and the Nigeria Police Brutality Register.Impunity Loop
Post-Iva Zikist suppression (1950–51) — colonial security services arrested Zikist Movement leaders and proscribed the organisation under the Emergency Powers Order in Council (1949).
Eastern Region political crisis (1953) — Azikiwe's NCNC government in Enugu faced an internal revolt by the 'Sit-Tight' faction. Lyttleton dispatched commissioners; the crisis fed into the 1953 inter-regional motion that began the federal restructuring.