The subject of the painting is from The Faerie Queene, by Edmund Spencer, written in 1596 as an allegory of the Tudor dynasty, linking it with the Arthurian tradition. The painting depicts Una, the personification of truth, the Protestant church. She is confronted by a fierce lion while looking for her lost Red Cross Knight. As a representative of holiness, the Knight was commanded to escort Una to rescue her family from a dragon, until evil forces separated them. The lion, symbolising honour, sees Una's sorrow; recognising her beauty and truth, he vows to be her guard.