After a short, unsatisfactory stay in Egypt, Cambyses set out on his return to Persia. While on his way home, news was brought to him that his brother Smerdis had usurped the throne. A Magian [Footnote: There were at this time two opposing religions in Persia: Zoroastrianism, which taught the simple worship of God under the name of Ormazd; and Magianism, a less pure faith, whose professors were fire-worshippers. The former was the religion of the Aryans; the latter, that of the non-Aryan portion of the population. The usurpation which placed Smerdis on the throne was planned by the Magi, Smerdis himself being a fire-priest.] impostor, Gomates by name, who resembled the murdered Smerdis, had personated him, and actually grasped the sceptre. Entirely disheartened by this startling intelligence, Cambyses in despair took his own life. REIGN OF DARIUS I. (521-486 B.C.).--The Persian nobles soon rescued the sceptre from the grasp of the false Smerdis, and their leader, Darius, took the throne. The first act of Darius was to punish, by a general massacre, the Magian priests for the part they had taken in the usurpation of Smerdis. [Illustration: CAPTIVE INSURGENTS BROUGHT BEFORE DARIUS. Beneath his foot is the Magus Gomates, the false Smerdis. (From the great Behistun Rock.)] With quiet and submission secured throughout the empire, Darius gave himself, for a time, to the arts of peace. He built a palace at Susa, and erected magnificent structures at Persepolis; reformed the administration of the government (see p. 82), making such wise and lasting changes that he has been called "the second founder of the Persian empire"; established post-roads, instituted a coinage for the realm, and upon the great rock of Behistun, a lofty smooth-faced cliff on the western frontier of Persia, caused to be inscribed a record of all his achievements. [Footnote: This important inscription is written in the cuneiform characters, and in three languages, Aryan, Turanian, and Semitic. It is the Rosetta Stone of the cuneiform writings, the key to their treasures having been obtained from its parallel columns.] And now the Great King, Lord of Western Asia and of Egypt, conceived and entered upon the execution of vast designs of conquest, the far-reaching effects of which were destined to live long after he had passed away. Inhospitable steppes on the north, and burning deserts on the south, whose shifting sands within a period yet fresh in memory had been the grave of a Persian army, seemed to be the barriers which Nature herself had set for the limits of empire in these directions. But on the eastern flank of the kingdom the rich and crowded plains of India invited the conqueror with promises of endless spoils and revenues; while on the west a new continent, full of unknown mysteries, presented virgin fields never yet traversed by the army of an Eastern despot. Darius determined to extend the frontiers of his empire in both these directions.