First Franco - Dahomean War The First Franco - Dahomean War , which raged in 1890 , was a major conflict between France , led by General Alfred - Amédée Dodds , and the Dahomey under King Béhanzin . The French emerged triumphant after they won at the Battle of Abomey and incorporated Dahomey into their growing colonial territory in West Africa . Background . At the close of the 19th century , European powers were busy conquering and colonizing much of Africa . In what is today Benin , the main colonial power was the French Third Republic . 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 Kingdom of Dahomey . In 1851 , a Franco - Dahomean friendship treaty was ratified allowing the French to operate commercially and missionaries to enter the country . By 1890 , the Fon kingdom of Dahomey was at the height of its power . It laid claim to almost all the coast of modern Benin plus much of south - central Benin as far north as Atcheribé . One of Dahomey ' s most important tributaries was the small kingdom of Porto - Novo near the coast . The kingdom had been at odds with Dahomey on and off since the middle of the 18th century . In 1861 , Porto - Novo was attacked by British anti - slaving ships . Porto - Novo asked for and received French protection in 1863 , but this was rejected by Dahomey . 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 . Dahomey ignored all French claims there as well and continued to collect customs from the port . Cause of war . In 1874 , King Tofa took power in Porto - Novo and re - established French protection over the kingdom after Dahomey attacked it in 1882 . Dahomey continued raiding the town , which culminated in an incident that brought the Fon and French into war . In March 1889 , Dahomey attacked a village on the Ouémé where a village chief under the protection of the French . After remarking that the flag of the tri - color would protect him , the Fon commanded one of his Dahomey Amazons to behead him and wrap his head in the flag . 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 . The crown prince and later king Béhanzin received the mission but nothing was achieved other than mutual distrust . Opening of hostilities . 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 . On February 21 , the French arrested the senior Fon officials in Cotonou and began fortifying the town . Skirmishes with local militia also broke out . It wasn ' t long before word of this got back to Abomey . Dahomey sent a force straight to Cotonou with plans to bring it firmly back under Fon control once and for all . Battle of Cotonou . On March 4 , a Dahomey army of several thousand charged the log stockade around Cotonou at approximately 5 in the morning . This was usual for the Fon army of Dahomey that almost always marched at night and attacked just before dawn . Prying apart the stakes and shoving their muskets through , the Fon fired into the enclosure . Some even managed to surmount the 800 - meter perimeter inflicting casualties within the walls . After four hours of intense fighting , often occurring hand - to - hand despite withering French firepower and even gunboat shells , the Fon force withdrew . The French sustained few losses , but the Fon suffered several hundred dead ( 129 within the French lines ) . Battle of Atchoupa . After regrouping , Dahomey sent another force south , this time toward Porto - Novo . After receiving numerous reinforcements , the French ordered between 350 - 400 men with three field guns to march north and intercept the Fon . This time , the French would be assisted by warriors from the kingdom of Porto - Novo . Some 500 of King Tofa ' s warriors marched ahead as a screening force . Barely 4 miles outside of their target , the Dahomey army encountered and routed the Porto - Novo force . A group of tirailleurs fighting alongside the group did hold its ground , allowing the rest of the French force to form a defensive square . For over two hours , the Fon attacked the French square with numerous charges forcing . The Dahomey force was able to fight the French all the way back to Porto - Novo before breaking off the attack and returning without taking the city . End of hostilities . Dahomey did not launch any further attacks on Cotonou or Porto - Novo . On October 3 , 1890 , Dahomey signed a treaty recognizing the kingdom of Porto - Novo as a French protectorate . Béhanzin was also forced to cede Cotonou , but did receive 20 , 000 francs a year for giving up his customs rights . The war was a resounding victory for France and a humiliating , though eye - opening , experience for Dahomey . Despite the treaty , both sides believed peace could not last and made preparations for another decisive encounter .