The slave trade was the economic basis of African states like Oyo, Dahomey, Benin and Asante and Zanzibar. Before the arrival of the Europeans in the 16th century, the majority of slaves were exported from Zanzibar East Africa which was an important slave centre for the Arabs. Following the overland slave caravan routes across the Sahara from the Sahel to North Africa and the Arabian peninsula.They could never imagine that their African brethren would be treated badly because to them, slaves should be treated like humans and slavery only had household or governmental aspect:
With increasing European presence, competition and rivalry among Europeans grew in particular for the right of acquiring slaves from their African and Arab agents But as the demand for slaves rose, tribal wars and raids became the main source of supply
The Kingdom of Dahomey, Abomey (Allada, and Whydah were its provinces) one of West Africa's principal slave states was situated in modern day Benin. The kingdom was founded in the 17th century and survived until the late 19th century, when it was conquered by the French and incorporated into France's West African colonies.
In the early 18th century, Kings of Dahomey played an active part in the slave trade. The Bight of Benin was the second largest exporter of captives, after West Central Africa. African monarchs along the Slave Coast, the Pepper Coast, Ivory Coast and Guinea Coast of West Africa amassed fortunes selling slaves to European dealers.
King Tegbesu the sixth King of Dahomey was by the 1750's, estimated to have a slave-based annual income of £250,000. His son, Kpengla, was responsible for expanding the empire into what is currently Togo, and waging war on those who would interfere with Dahomeys stronghold on the slave trade.
King Gezo (Ghezo) of Dahomey (1818-1858) He is famous for taking the kingdom to its highest point of its power and fame, his bloodthirsty reputation, and his women warriors, which he used in wars over the slave trade, between Dahomey and Egba (Yoruba Nation). After about 1840, as Britain had put an end to the overseas slave trade, Gezo turned to palm oil exports, and slaves, would now remain to work palm plantations. Palm oil was much less lucrative than slaves, and the economy began to crumble during King Glele's reign (1858–89).
By the time King Behanzin (1889–94) came to power, hostilities were running high. In 1892 the French Colonel Alfred-Amédée Dodds defeated the Kingdom of Dahomey and King Behanzin was deported to the West Indies.