 In 844 and 865, the monastery of S. Ambrogio in Milan purchased land in the "concilium" of Castel S. Pietro which would have included Balerna.In the 12th century some "decimani" (tithe collectors) and the monastery of S. Abbondio in Como owned land and associated rights in Balerna.By no later than the 12th century, Balerna was as the center of a pieve, which encompassed the area that is now the district of Mendrisio except for Chiasso (which was part of the pieve of Zezio) and some areas of the Pieve of Riva San Vitale.