Pre-colonial — slave wars, ritual killing and the Old Town Massacre (pre-1900) — Cross River State

Old Calabar slave-trade depopulation (c. 1670–1841) — c. 1.2 million people embarked at the Cross River for the Americas; the demographic collapse of the interior Aro and Ekoi corridor.
Old Town Massacre, 1767 — British captains of the slave ships *Edgar*, *Indian Queen*, *Duke of York* and *Nancy* lure the Obutong (Old Town) royal house aboard and shoot them in a trade-war proxy fight for Duke Town; the surviving Robin John brothers are sold into Dominica slavery and eventually return as Christian converts. Pattern: commercial violence / Atlantic capital.
Killing of twins (pre-1880s) — Efik–Ibibio belief that twins were *abasi*-cursed produced systematic infanticide until Mary Slessor's campaigns in Okoyong and Itu (1888–1915); the Twins Mothers' Refuge at Use-Offot became the template for later mission orphanages.
Ekpe judicial executions — the Ekpe leopard society's *mboko* enforcement included property seizure, exile and capital punishment under nsibidi sentence; documented in the Antera Duke Diary (1785–88).
Anglo-Calabar gunboat actions, 1850s–1880s — RN punitive shellings of Creek Town and Duke Town over the *egbo* (Ekpe) tax on British supercargoes; the Hewett Treaty (10 Sept 1884) closes the cycle.