Cotentin is part of Normandy. The name refers to the city of Coutances, formerly Constantia, after the Roman emperor Constantius. The largest city on the peninsula is Cherbourg-en-Cotentin in the north, but the southern towns of Saint-Lô, Villedieu-les-Poêles, and Granville are also part of the historical province. This peninsula is a natural region, called the Péninsule du Cotentin. Nowadays, the name Cotentin is often restricted to this area, and even Coutances itself is excluded. The Channel Islands were originally part of the historical province of Normandy, but in 1790, it was divided into two departments: Manche and Calvados.