Most scholars agree, however, that Cyrus the Great was at least the second of the name to rule in Persia. One cuneiform text in Akkadian--the language of Mesopotamia (present-day Iraq) in the pre-Christian era--asserts he was theson of Cambyses, great king, king of Anshan, grandson of Cyrus, great king, king of Anshan, descendant of Teispes, great king, king of Anshan, of a family [which] always [exercised] kingship.In any case, it is clear that Cyrus came from a long line of ruling chiefs.

The most important source for his life is the Greek historian Herodotus. The idealized biography by Xenophon is a work for the edification of the Greeks concerning the ideal ruler, rather than a historical treatise. It does, however, indicate the high esteem in which Cyrus was held, not only by his own people, the Persians, but also by the Greeks and others. Herodotus says that the Persians called Cyrus their father, while later Achaemenian rulers were not so well regarded. The story of the childhood of Cyrus, as told by Herodotus with echoes in Xenophon, may be called a Cyrus legend since it obviously follows a pattern of folk beliefs about the almost superhuman qualities of the founder of a dynasty. Similar beliefs also exist about the founders of later dynasties throughout the history of Iran. According to the legend, Astyages, the king of the Medes and overlord of the Persians, gave his daughter in marriage to his vassal in Persis, a prince called Cambyses. From this marriage Cyrus was born. Astyages, having had a dream that the baby would grow up to overthrow him, ordered Cyrus slain. His chief adviser, however, instead gave the baby to a shepherd to raise. When he was 10 years old, Cyrus, because of his outstanding qualities, was discovered by Astyages, who, in spite of the dream, was persuaded to allow the boy to live. Cyrus, when he reached manhood in Persis, revolted against his maternal grandfather and overlord. Astyages marched against the rebel, but his army deserted him and surrendered to Cyrus in 550 BC.