Now three feet and now twain to use,
And still more feebly o'er the plain
Walketh with three feet than with twain?"

And Oedipus made reply--

"'Tis man, who in life's early day
Four-footed crawleth on his way;
When time hath made his strength complete,
Upright his form and twain his feet;
When age hath bowed him to the ground
A third foot in his staff is found."

And when the Sphinx found that her riddle was answered, she cast herself
from a high rock and perished. Now for a while Oedipus reigned in
great power and glory; but afterwards his doom came upon him, so that in
his madness he put out his own eyes. Then his two sons cast him into
prison, and took his kingdom, making agreement between themselves that
each should reign for the space of one year. And the elder of the two,
whose name was Eteocles, first had the kingdom; but when his year was
come to an end, he would not abide by his promise, but kept that which
he should have given up, and drave out his younger brother from the
city. Then the younger, whose name was Polynices, fled to Argos, to King
Adrastus. And after a while he married the daughter of the King, who
made a covenant with him that he would bring him back with a high hand
to Thebes, and set him on the throne of his father. Then the King sent
messengers to certain of the princes of Greece, entreating that they
would help in this matter. And of these some would not, but others
hearkened to his words, so that a great army was gathered together and
followed the King and Polynices to make war against Thebes. So they came