Pre-colonial era (pre-1900)

Aro slave-raids in Wawa territory (c. 1820s–1890s) — Aro Confederacy mercenaries (Abam, Ohafia, Edda) raided Awgu, Udi, Nkanu and Nsukka villages on behalf of the Long Juju oracle at Arochukwu. Captives marched to Bonny and Calabar for the trans-Atlantic and (after 1807) Brazilian-illegal trade. Depopulation patterns are still visible in 19th-century village-group density data.
Igala raids from Idah (c. 1850s–1880s) — southern wave of the Sokoto jihad reached Nsukka via the Igala kingdom; defensive hilltop settlements at Eha-Amufu, Obollo and Ette date to this era.

Methodology

Tier 1 · primary

Courts. Gazettes. National archives.

Tier 2 · corroborating

OCCRP. HRW. BudgIT. TheCable.

Tier 4 · tertiary, flagged

Wikipedia only where primary is pending. Always labelled.