 The name Gerra is probably from the 18th Century, when the village of Ronco de Martignoni (which was first mentioned in 1591) expanded into the Gerra river delta and the shores of Lake Maggiore.Gerra was part of the old "Vicinanza" of Gambarogno.In the 16th Century, Ronco de Martignoni, Ronco di Sopra and Scimiana joined together to form an independent municipality.