Saint Piran is the patron saint of Cornwall, a region in the southwest of England. He is believed to have lived during the 5th or 6th century and is often associated with the introduction of tin mining to the area. His feast day is celebrated on March 5th, which is also recognized as Saint Piran's Day. The legend of Saint Piran includes a story of him arriving in Cornwall on a millstone, which symbolizes his connection to the land. He is often depicted with a black cross on a white background, representing the Cornish flag. His legacy continues to be celebrated in Cornwall through various cultural events and traditions.