The territorial entity that is today the municipality of Zagnanado has undergone several administrative changes since the colonial period until today. Since the early eighteenth century, the region depended on the kingdom of
Abomey. Guézo made the area headquarters of the army during his campaigns against the
Yoruba and Kétou of Abeokuta. By the Act of June 21, 1895, King
Agoli-Agbo, he authorised full authority over the
Agonlin region. In the early twentieth century, Zagnanado and surrounding villages were visited by many missionaries who spread
Christianity. During the colonial period and into the 1970s, Agonlin remained a single administrative entity. However, in 1978 it was divided into three communes, Zagnanado,
Covè and
Ouinhi. ==Geography==