In the place where the church dedicated to San Secondo stands, martyr of the Theban legion, there was an older church, lower and with a single nave built in an earlier period probably by Benedictine monks, around which the ancient village of Magnano was built. In the first half of the 11th century the church was raised and enlarged until it roughly assumed its present appearance.
The church has had a rather troubled history. Originally built when around it there was the ancient village of Magnano, it subsequently lost its relevance when, starting from the end of the fourteenth century, the population moved higher (where the current municipality of Magnano is located). At the beginning of the seventeenth century the role of parish was taken over by the new church of Santa Marta and there was no longer any reason to keep the ancient Romanesque church: it was therefore established, in 1606, that it was demolished to reuse the building material for the new church. The faithful, however, opposed this decision and obtained that it remain active: thus it proceeded to its arrangement with baroque additions. During the 19th century the church was once again left to decay. Only in 1968 was it decided by the Province of Vercelli and the Superintendency of Piedmont to renovate the religious building and restore its original Romanesque appearance.