The national flag of Cornwall is St. Piran's flag - a black background with a white cross.
According to folklore, St. Piran sailed to Cornwall from Ireland on a stone. He had offended one of the Irish kings who shackled him to a millstone and threw him into the sea. The people were amazed to see him rise to the surface astride the stone. He landed in Cornwall, where he built his church at Perranporth.
According to legend, one night as St. Piran was preparing his dinner, his rectangular hearth cracked in the heat of the strong fire. The black rocks became so hot that he noticed shining white metal in the shape of a white cross appeared among the black ash.
This was the discovery of the smelting process which St. Piran taught to the Cornish. In Cornwall, we celebrate St. Piran's Day on March 5th.
