Pre-colonial / 19th c. (pre-1900) — Lagos State

c. 1600 — Awori–Bini founding war. The Awori settlement on Iddo/Eko is incorporated into the Benin Empire under Oba Orhogbua; a Bini garrison is installed at Eko (the name itself is the Bini word for "war camp"). The Olofin/Awori dispersal that follows seeds Isheri, Ojo, Otta and Ado-Odo — the deep substrate every later Lagos crisis rides on.
1775–1851 — Eko as a Bight slaving entrepôt. Under Obas Akinsemoyin, Ologun Kutere, Adele and Kosoko, Lagos becomes one of the four largest slave-export ports on the Bight of Benin (~25,000 enslaved persons shipped 1840–48 alone). The throne is a contested commercial office; every succession from Adele I (1775) onwards is a coup, an exile or a foreign-backed restoration.
26–28 Dec 1851 — Royal Navy bombardment of Lagos ("Reduction of Lagos"). Commodore Henry Bruce's squadron (HMS Bloodhound, Teazer, Volcano, Sampson, Penelope, Waterwitch) shells Eko for two days, lands a 300-Marine assault force, burns the war canoes and deposes Oba Kosoko, installing Akitoye under a "treaty against the slave trade." British casualties: 15 killed, 75 wounded. Lagosian dead: unrecorded; estimated several hundred. This is the template for every later British coastal punitive expedition — Brass 1895, Benin 1897, Aro 1901–02, Ijemo 1898. *Pattern: imperial coercion · maritime bombardment.*
6 Aug 1861 — Cession Treaty of Lagos. Oba Dosunmu (Akitoye's son), under naval gun and threat of deposition, cedes Lagos and its waters to Queen Victoria; Acting Consul William McCoskry hoists the Union Jack at Government House. The £1,200/year "pension" to the Oba is the first formal subordination of a Nigerian crown to the British exchequer.
1892 — Lagos as logistics base for the Ijebu-Ode War. The 1,000-strong Hausa/Yoruba expedition that storms Ijemu/Imagbon is mustered, provisioned and re-embarked at Lagos; Lagos market women finance much of the carriage.