The arrival of the Walser and the colonization of the head valley of Sesia, increased the community of Pietre Gemelle's population, culture and wealth. The colonized territory with their new inhabitants were dependant on the parish of San Michele, Riva. The inhabitants were extremely devoted Catholics and was tightly linked to the church and its sacraments. Every Sunday the people walked to participate in the proceedings even during winter through snow, ice and the occurrence of avalanches made their journey arduous at times. Soon the constant increase in the number of people and hamlets north of Riva voiced the necessity of their own parish, but added to this was the difficulty to communicate with a clergy representative who couldn't speak German and the confessions could surely not be mediated by a translator! In 1475 independence was granted to them and the first parish was an oratory built in the hamlet, Pedelegno. In the meanwhile they started contemplating a bigger church which was erected in the same area where the church San Giovanni Battista is situated today.