The patron of San Donato Val di Comino is Saint Donatus, bishop and martyr (san Donato vescovo e martire), celebrated on 7 August; the origins of the festival are lost in the Middle Ages (8th century AD), when the territory was held by the Lombard Duchy of Spoleto. A torchlight procession on the night between 6 and 7 August, the night of the eve, accompanies the pilgrims who will keep the long vigil in the sanctuary; of the ancient traditions practically everything has remained unchanged, such as the novena, the arrival of the pilgrims, the popular hymn, the night vigil, the rite of dressing the saint carried out by the confraternity and the procession through the alleys of the medieval village.
On the last Sunday of August Santa Costanza, co-patroness of the town, is celebrated: her remains were brought to San Donato Val di Comino in 1756 and she was immediately raised to co-patroness. The festival includes a costume re-enactment, popular games of the 1700s and 1800s, a night vigil, the eighteenth-century «Mercatino di Santa Costanza», fireworks, concerts and a solemn procession in which the saint is carried in triumph by 12 pages in eighteenth-century dress.
