Pre-colonial (pre-1900)

Aro slave-raids on Igbo hinterland (17th–19th c.) — Aro middlemen with armed escorts drew slaves from across Anambra-bank villages; the *Ibini Ukpabi* oracle at Arochukwu was the judicial authority. Ended by the 1901–02 Anglo-Aro War.
Nri ritual-zone disputes (18th–19th c.) — non-violent in Nri's own peace-mark territory but boundary clashes recorded between Nri and Aguleri / Umueri lineages over Eri ancestral land.

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.