Darius I - King of Persia from 521 to 485 B.C.; son of Hystaspes. The sources for the history of Darius are his own trilingual inscription at Behistun, the Babylonian contract tablets, and the accounts which the Greeks from Herodotus onward have given. Herodotus is corrected repeatedly by Ctesias. The older branch of the Ach?menides died out with Cambyses and his brother, the true Smerdis, while the head of the younger branch, which traced its descent to Teispes, was Hystaspes, governor of Parthia, who submitted to the new ruler. His son Darius, however, undertook to win back the scepter from the Magian Gaumata, who had assumed the title of king and had married Cyrus' daughter. Darius and six intimate companions of noble blood, relying on the protection of Ahuramazda, attacked the usurper on the 10th of Tishri (Oct. 16), 521, at a city in Media, and killed him; Darius now became king. In Persia itself Darius was confronted by a new pretender, a second pseudo-Smerdis. In addition, the subject nations throughout the East (for instance, the Elamites, Medians, Parthians, Hyrkauians) tried to win back their independence, and placed at their head men who claimed descent from the royal family. The most serious rebellion was the one in Babylon under Nidintabel, who called himself Nebuchadnezzar III., the son of Nabonid. The first Babylonian record of Nebuchadnezzar III.'s reign is dated Tishri 17 (Oct. 23) of the year of his accession, 521. [Jewish Encyclopedia]

Darius I "the Great" (549-486 BC) was a king of Persia who ruled for 35 years, from September 522 BC to October 486 BC. He was the third Achaemenian king and was considered by many to be ?the greatest of the Achaemenian kings.? During his reign, Darius completed the work of his predecessors and not only did he ?hold together the empire,? but he also extended it in all directions. Thus, with Darius as Great King, Achaemenian Persia became the largest empire in the world. Darius was responsible for more than just the expansion of the empire. He also centralized the administration of the empire, encouraged cultural and artistic pursuits, introduced legal reforms and developed juridical systems. In addition, many large building projects were started under Darius? rule, including the construction of a new capital city called Persepolis. As much as Darius? reign can be characterized by these achievements, it can also be characterized by a number of upheavals and battles, and general unrest among the citizens. There were two revolts in Babylonia and three in Susania. The Ionian Revolt lasted from 499 to 493 BC, and was a large-scale rebellion by many regions of Asia Minor against Persian rule. Darius planned an expedition to Greece in order to punish the Greeks for supporting the Ionian Revolt. His health, however, began to fail and he chose Xerxes I, his oldest son by Atossa, to be his successor. He never went to Greece as he died in Persis in October 486 BC. [Ancient History Encyclopedia]