History of Nigeria by Alan Burns (1929) The Colony of Lagos

In January 1854 the Consul presided at a ‘palaver’ between the two parties, and an agreement was come to by which Kosoko was recognized as King of Palma and Lekki as a condition of his relinquishing all claim to the throne of Lagos. 
...
In June 1861 the Foreign Secretary instructed the Consul to arrange for the occupation of Lagos .. [eventually bombarded in December]
...
Very much against the will of Dosumu, Kosoko and his principal lieutenant, Tappa, were now

allowed to return to Lagos, and in 1863 Kosoko ceded Palma and Lekki to the Government in return for a pension, which he drew until his death in 1872.

Badagri, Palma, and Lekki were the first additions to the Colony; in 1863 Ado and Oke-Odan, to the west of Lagos, were added, and between 1883 and 1895 Appa, the Itsekiri country as far as Mollume, Ogbo Mahin, Ijebu-Ro, Itebu, Aiyesan, Igbessa, Ilaro, and Kotonu were included in the Lagos territories.

Kotonu was, however, exchanged with the French in 1889 for Pokra, a district north of Badagri.

* Kosoko (Headman) and His Wife - Illustrated London News (January 8, 1898)

This was posted by Mr @kehinde Thompson on Nigeria Nostalgia Group.