Chiasso is first mentioned in 1140 as
Chiasso (and Boffalora)
Historically, Chiasso and Boffalora were two distinct agricultural villages. Because of the presence of the nearby Italian border and customs office, and later as part of an access route to the St. Gotthard's Tunnel, the two villages merged and grew.
Chiasso's history and development were strongly influenced by its unique location. During its early history, a castle was built in Chiasso as part of the extended fortifications of the city of Como. It was a suburb of Como, until 1416 when it was incorporated in the Pieve ofBalerna and given to the Rusca family to manage. The houses in the village center were owned by the Albrici family and were granted imperial privileges. Chiasso had become an independent community sometime before 1552. In the contemporary documents, it is mentioned as Clasio tabernarum (Chaisso of taverns) referring to its function as a transit point.
Boffalora is mentioned in 1536 as a municipality and remained its independence until the second half of the 17th Century. They became a single parish either in 1657 or 1677.
Chiasso's church belonged to the Pieve of Zezio (in Como), from which it withdrew in the 16th Century. In 1888, Boffalora separated from the parish. It became the seat of an archpriest in 1928. The Church of San Vitale, was first mentioned in 1227, and was rebuilt in 1934.
In the 15th Century Chaisso was known for its horse market. However, the market ended after the invasion of the Swiss Confederationand the march through Chiasso in the War of the League of Cambrai in 1510. In the late 16th Century Chiasso had a small population when compared to other municipalities of the Mendrisiotto valley. The village survived through its role as a border town (providing warehouses and inns) along with income from agriculture and paper mills. In the 19th Century, tobacco and silk factories moved into the town.