The History Museum of Ouidah is located in
the former Portuguese Fortress.
Before the colonial time, the area today called Benin consisted of several kingdoms, the most powerful being the one of Allada, situated between Abomey and Ouidah. Abomey took over as the most important kingdom in the 18th and 19th century, and the kings of Abomey can be traced back to King Dakodonou, who was the first of the Abomey kings to rule large parts of the country 1610 – 1645. The new kingdom was called Dahomey, and changed name to Benin as late as in 1975. (The country bore the name Benin also for a short period by the end of the 19th century, to confusion with the old kingdom Benin located in Nigeria, today Benin City and Benin State, Nigeria).
France conquered and occupied Dahomey (southern Benin) in 1892-94, dismissing the king Gbehanzin, and the last king of Abomey, Agoli-Ago, ruled under French law. The current borders of Benin towards Burkina Faso and Niger were set in 1909 in a treaty between France and Britain. After a period being included in French West Africa, Benin was again a separate protectorat under France from 1958, and an independent state from 1960.
For more details on Benin’s history see for instance New Africa.com on Benin.