The Xwéda kingdom was located in the center of the “Slave Coast”, an area so designated by the European traders because it was the source of the majority of slaves exported to Europe and the New World . The Slave Coast encompassed the area from the River Volta in the west to the Lagos channel in the east, and is geographically distinguished by savannah type vegetation, as opposed to the tropical rain forest running to the east and west along the African coast. Though the area did not represent any one indigenous African political or ethnic unit, most of the inhabitants belonged to one ethno-linguistic entity, known as Aja-Ewe. The kingdoms of Allada, Xwéda, and Dahomey all spoke an Aja-Ewe language variants .
The kingdom of Xwéda was located along the coast, bordered by the kingdom of Allada to the north. Its capital was Savi (near the present-day village of Savi ), and it conducted trade through the port of Gléwé (modern-day Ouidah). The Xwéda society was controlled by a king and his subordinate governors or chiefs. The king “owned” all of Xwéda and its inhabitants, and also held a religious position in the culture. The kingdom and particularly Savi were densely populated in 17 th and 18 th centuries. One French trader observed that Xwéda was “so populated with dwellings and inhabitants that it can be said to form a single town.” The vastness of the population made cultivable land scarce – Europeans reported that there was hardly any land uncultivated in the 17 th century. Because of this, a single poor harvest could and did lead to wide scale famine in the kingdom.
As with other societies along the West African coast, the inhabitants and their leaders practiced the Vodun religious tradition. In Xwéda, the best documented national religion is that of Dangbe, the snake god, to whom pythons were sacred. Dangbe was primarily concerned with regulation of rainfall and with agricultural fertility, but was also honored as the chief deity of Xwéda and sponsor of Xwéda's military success.
The founding of Xwéda is presumed to have taken place around 1500 AD, but its ascendancy among Slave Coast societies began in the 1680s, when Xwéda managed to usurp much of the European trade in slaves from the kingdom of Allada . By controlling the lion's share of the slave trade, Xwéda managed to shift wealth and therefore power to itself. After 1690, however, periodic conflicts and trade wars between Allada and Xwéda often disrupted Xwéda's trade with the Europeans, and by 1714 Allada succeeded in reacquiring a large portion of the trade they had lost. After 1714 the trade war escalated further due the internal political situation in Xwéda: King Huffon (who as a child had been installed as figurehead king) matured and began to exert power over his chiefs, who had governed in Huffon's stead during his childhood. These chiefs went so far as to approach the King of Allada to take action against Huffon, prompting Allada to further inhibit Xwéda trade. Though relations between the two states improved on the death of the king of Allada in 1717, the relationship again deteriorated soon after, and remained poor until the capture of Allada by Dahomey in 1724.
In March of 1727, King Agadja of Dahomey mounted an attack on Xwéda, seeing an opportunity presented by a schism between Xwéda's King Huffon and his chiefs. Though Xwéda presented a larger force than Dahomey , the villages to the north of Savi were easily defeated. The Xwédan failure to mount a guard at the river to the north of Savi allowed Dahomey to cross easily and approach Savi. The residents of Savi fled to Gléwé, and the Dahomians burned Savi and brutally laid waste to Xwéda. Dahomey reportedly slaughtered over 5,000, and up to 11,000 others were imprisoned. The ruins of the palace complex held such political significance that Agaja forbade Xwédas from resettling in direct proximity to the palace. The Xwéda kingdom never recovered from this defeat, and the area was thereafter controlled by Dahomey .