Giovanni Castelmur was born in 1800 in Stampa and raised in Marseille, where his family owned a pastry shop. Consistent with the family tradition, he and his brother, Bartolomeo, left home. After becoming a successful businessman and receiving the title of baron, Giovanni returned to Bregaglia determined to restore prestige to the family name. Ever since the Late Middle Ages, the Castelmur family was among the most politically and economically influential families of the region. However, in the centuries that followed, their power diminished as they were overshadowed by more prominent families, such as the Salis family. Giovanni Castelmur purchased the hill of Nosa Donna, where there is a church tower dating back to the Middle Ages and the dilapidated Santa Maria church dating back to the Reformation. Although he and his wife never had children, he made a family mausoleum out of the church. He and his wife, Mrs. Anna Castelmur, who was also his first cousin, were buried in the crypt of the church. The busts of both can be seen at the entrance to the church.
Giovanni Castelmur was barely 30 years old when he became a property owner. In addition to being a successful businessman, he also established himself as a philanthropist and supporter of the arts.
He was determined to legitimize his nobility by acquiring a title. At some point, he was bestowed the title of baron, which he also passed on to his wife, the baroness. The manner in which he received the title is questionable. It is believed that he may have purchased the title, since all his life he had tried to confirm the legitimacy of his family's noble status. Even his indirect relatives used the baron title up until the late 2000s.
To this day, the baron and baroness are recognized for their charitable contributions and for having supported various institutions and public works projects.