The two top figures are: the Emperor Constantine (left) and his mother, the Empress Saint Helena, holding the True Cross which she has found (right). There are at least three legends beginning with that of Saint Ambrose, describing how Saint Helena found the True Cross and distinguished it from those of the thieves. The inscriptions tell us the saint, bottom left, is Saint Nicholas, and that the other is Saint Spyridon, both of whom are said to have been present at the 1st Council of Nicea (325) summoned by Constantine. Saint Spryidon was a shepherd before being elected Bishop. He retained his shepherd's cap and his herd while in office. He is said to have cured Constantine of an ailment. The whole picture is neatly tied together.