Having discovered a conspiracy in which the son of Parmenio was implicated, he put both father and son to death, though Parmenio himself was innocent of any knowledge of the affair. This cruel injustice excited universal displeasure. In 329 he penetrated to the farthest known limits of Northern Asia, and overthrew the Scythians on the banks of the Jaxartes. In the following year he subdued the whole of Sogdiana, and married Roxana, whom he had taken prisoner. She was the daughter of Oxyartes, one of the enemy's captains, and was said to be the fairest of all the virgins of Asia. The murder of his foster-brother, Clitus, in a drunken brawl, was followed, in 327 B.C., by the discovery of a fresh conspiracy, in which Callisthenes, a nephew of Aristotle, was falsely implicated. For challenging Alexander's divinity, he was cruelly tortured and hanged. In 327 B.C., proceeding to the conquest of India, hitherto known only by name, Alexander crossed the Indus near to the modern Attock, and pursued his way under the guidance of a native prince to the Hydaspes (Jhelum). He there was opposed by Porus, another native prince, whom he overthrew after a bloody contest, and there he lost his charger Bucephalus; thence he marched as lord of the country, through the Punjab, establishing Greek colonies. He then wished to advance to the Ganges, but the general murmuring of his troops obliged him, at the Hyphasis (modern Sutlej), to commence his retreat. On regaining the Hydaspes, he built a fleet, and sent one division of his army in it down the river, while the other followed along the banks, fighting its way through successive Indian armies. At length, having reached the ocean, he ordered Nearchus, the commander of the fleet, to sail thence to the Persian Gulf, while he himself struck inland with one division of his army, in order to return home through Gedrosia (Beluchistan). During this march his forces suffered fearfully from want of food and water. Of all the troops which had set out with Alexander, little more than a fourth part arrived with him in Persia (325 B.C.). [Illustration: Alexander discovering the Body of Darius.] At Susa he married Stateira, the daughter of Darius, and he bestowed presents on those Macedonians (some ten thousand in number) who had married Persian women, his design being to unite the two nations. He also distributed liberal rewards among his soldiers. Soon afterward he was deprived, by death, of his favorite Hephestion. His grief was unbounded, and he interred the dead man with kingly honors. As he was returning from Ecbatana to Babylon, it is said that the Magi foretold that the latter city would prove fatal to him; but he despised their warnings. On the way, he was met by ambassadors from all parts of the world--Libya, Italy, Carthage, Greece, the Scythians, Celts, and Iberians.