This drawing deals with the mythological tale of the riddle of the Sphinx. The answer to her question: 'What walks on four legs in the morning, two at noon, and three in the evening?' is Man (in infancy, adulthood and old age, walking with a stick). Here Youth is shown dying, Man is staring at the Sphinx and Age is climbing the rock.
The idea to have Youth dying may have been prompted by the premature death of Oliver, son of Ford Madox Brown, at the age of only nineteen in November 1874. W. B. Scott claims to have suggested the subject of the Sphinx to Rossetti (Reminiscences, vol. 2, p. 3). Rossetti may have intended to produce a painting on the subject, but none was ever begun.
There is an earlier preliminary drawing in the Fogg Museum of Art, Cambridge, Massachusetts.