House of Visconti
In 1326 was testified that Sonvico and neighbors merged into a community known as The Castellanza. During the 16th century, the village of Cimadera joined The Castellanza. Sonvico was strategically located on top of Lugano valley, which was a necessary passage to the Nordic versant of the Alps, through the Gotthard Pass. Additionally, it was strongly fortified with a ring wall and a castle, which was built before 1326 and renovated around the end of the 15th century. These qualities made the Castellanza a strategic base for the House of Visconti and the House of Sforza of the Duchy of Milan until the Battle of Novara (1513).