MediumPisanello frescoes in the Ducal Palace, Mantua. Virgil, the Roman Poet who was from Mantua, sits on the left. In front of him, Perceval. Another warrior carries a shield with medieval emblems, including the three balls of mud that lay in holy golden vases underneath the St. Andrea’s basilica in Mantua. A pontifical Bulla states that those three mud balls were wet by the blood of Jesus Christ at his crucifixion. The three spheres were brought to Mantua by Longinus himself, the Roman centurion who had pierced Jesus with his spear, and right after acknowledged the holiness of the man he had tortured to death. Mantua is on the background, across the Inferior Lake that partly surrounds its castles.