Canosio is a high village of the Val Maira in the Piedmontese Alps, in the diocese of Saluzzo. In 1630 its people had grown cold in the faith; Calvinist preaching spreading from the neighbouring valleys had drawn many away from the sacraments. A few days after the feast of Corpus Christi that year, prolonged rains swelled the Maira until the torrent burst its banks. The water came down with such force that it rolled large boulders before it, and the houses clustered around the parish church lay directly in its path. The parish priest, Don Antonio Reinardi, rang the church bells to summon everyone, and in the crowded church he proposed a vow: if Canosio were spared, the village would celebrate a feast in thanksgiving every year, in perpetuity, within the octave of Corpus Christi.
The people accepted. Reinardi then took the Blessed Sacrament in the monstrance and walked out toward the torrent, accompanied by a group of the faithful singing the Miserere. Standing before the flood he raised the Host and gave the blessing. The accounts agree that the rain ceased immediately and the water fell back into its bed, leaving the village untouched. Many of those who had witnessed it returned to the practice of the faith, and the episode is remembered locally above all for the conversions that followed it.
The written record is thin, and the village itself says so: the original documents in the parish archive were burned during the seventeenth-century wars between France and Spain that passed through these valleys, and only a copy of the priest's own first-hand account survives. No formal ecclesiastical judgment on the event is known. What has endured is the vow: nearly four centuries later the people of Canosio still keep their annual feast in the octave of Corpus Christi, with the procession of the Blessed Sacrament through the village, and the Vatican International Exhibition lists Canosio among the Italian Eucharistic miracles.