- Benin–Idah War (1515–16) — Oba Esigie defeats the Igala Attah at Idah; the Iyoba Idia leads troops in the field (the bronze pendant mask of Idia commemorates this campaign). Pattern: imperial war.
- Benin–Ekiti / Owo / Akure campaigns (17th–19th c.) — sustained imperial wars across the Yoruba periphery.
- Atlantic slave-restraint policy (16th–18th c.) — Benin uniquely restricts male-slave exports; Itsekiri and Ijaw middlemen at Ughoton handle most of the limited trade.
- 19th-century inland contraction wars — losses to Aboh, Itsekiri, and the Yoruba states; the imperial frontier collapses by Adolo's reign (1848–88).
Edo State · Crisis deep dive
Pre-colonial — imperial wars and Atlantic restraint (pre-1897)
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.