• General Notes

  Darius I, called The Great (558?-486 BC), king of Persia (521-486 BC), son of the Persian noble Hystaspes, and a member of a royal Persian family, the Achaemenids.
  In 522 BC, on the death of King Cambyses II, a group of Magian priests tried to give the throne to one of
  their number, the usurper Gaumata; he pretended to be Smerdis (died about 523 BC), the murdered brother of Cambyses II. In 521, Darius defeated Gaumata and was chosen king of Persia.
  The first two years of his reign were occupied with suppressing rebellions, the most important of which occurred in Babylonia. Thereafter he devoted himself to reforming the internal organization of Persia and making its outer borders secure. He reorganized the vast empire into 20 satrapies, built highways, organized a postal system, reformed the currency, encouraged commerce, and won the goodwill of large portions of the heterogeneous population.
  Because he respected their religions, he was honored by the Jews, whom he permitted to complete the
  rebuilding of the Temple at Jerusalem in 516; by the Egyptians, whose high priest he consulted; and by the Greeks of Asia Minor, whose oracles supported him during the revolt of the Greek cities. In protecting the borders of the empire, Darius conquered new territories along the Indus River in the east and in the Caucasus Mountains in the northeast, but his expedition in 516 against the tribes of the Danube River failed.
  In 499 a revolt broke out among the Ionian Greek cities of Asia Minor, partly encouraged by some of the Greek cities on the mainland. The revolt was suppressed by 493, and Darius prepared to punish the mainland Greeks for their intervention. In 492 an army under Mardonius, the son-in-law of Darius, crossed the Bosporus into Thrace but was unable to reach Greece because the supply ships were wrecked off Mount Áthos. Two years later, a strong Persian force under the joint command of Artaphernes (flourished 5th century BC), a nephew of Darius, and the Mede commander Datis (flourished 5th
  century BC) invaded Greece from the north but was defeated at Marathon.
  A third expedition was being prepared when Darius died. He left a detailed account of his reign, inscribed in three languages on a towering rock. This Behistun Inscription, the first English transcription of
  which was complete in 1849, confirms many details of the life of Darius.
  Source: "Darius I," Microsoft(R) Encarta(R) 98 Encyclopedia. (c) 1993-1997

Details of DARIUS I 'The Great' King of 's family with ATOSSA of PERSIA