Casamance is the area of Senegal south of the Gambia including the Casamance River. It consists of the Lower Casamance (Basse Casamance, Baixa Casamança—i.e. Ziguinchor Region) and the Upper Casamance (Haute Casamance, Alta Casamança—i.e. Kolda Region and Sédhiou Regions). The largest city of Casamance is Ziguinchor.
The Casamance was subject to both French and Portuguese colonial efforts before a border was negotiated in 1888 between the French colony of Senegal and Portuguese Guinea (now Guinea-Bissau) to the south.