abstract:The Cathedral of Orvieto is a large 14th century Roman Catholic cathedral situated in the town of Orvieto in Umbria, central Italy. The building was constructed under the orders of Pope Urban IV to commemorate and provide a suitable home for the Corporal of Bolsena, a miracle which is said to have occurred in 1263 in the nearby town of Bolsena, when a traveling priest who had doubts about the truth of transubstantiation found that his Host was bleeding so much that it stained the altar cloth.