The French had established commercial ties with the indigenous peoples of the area including one of West Africa's most powerful states at the time, the Fon kingdom of Dahomey.

In 1851, a Franco-Dahomean friendship treaty was ratified allowing the French to operate commercially and missionaries to enter the country.

[2] Another issue of contention was the status of Cotonou, a port the French believed was under their control because of a treaty signed by Dahomey's representative in Whydah.

[3] Then in March of that year, France sent a mission to Dahomey's capital of Abomey to assert its claims to Cotonou and offer an annual payment.

[2] France responded to these events by building up its force in Cotonou to 359 men, 299 of which were Tirailleurs or French trained Senegalese and Gabonese.

[3] After four hours of intense fighting, often occurring hand-to-hand despite withering French firepower and even gunboat shells, the Fon force withdrew.

[6] After receiving numerous reinforcements, the French ordered 350 men with three field guns to march north and intercept the Fon.

[8] As the French column arrived to the village of Atchoukpa, Toffa's warriors, who were walking ahead of the formation, came under Dahomey fire and fled the battlefield in a complete rout.

[7] An attempt by King Béhanzin to send a detachment to bypass the French squares and sack Porto-Novo was thwarted by Colonel Terrillon.