Histories

Then the Spartans did as the Messenian advised; as they watched the mother of Aristodemus' children, they found her always preferring the elder when she fed and washed them, since she did not know why she was being watched. So they took the child that was preferred by its mother and brought it up at public expense as the first-born; and they called it Eurysthenes, and the other Procles.

They say that when these two brothers grew to manhood, they feuded with each other as long as they lived, and their descendants continued to do likewise.