But he would go farther, out into the immeasurable; the attraction to the infinite, to the comprehension and mastery of the universe, both intellectual and material, that lies in the nature of the yet inchoate uniform world-culture, finds its most vivid expression in its champion. When, indeed, he would advance farther and farther, from the Punjab to the Ganges and to the ends of the world, his instrument, his army, failed him; he had to turn back. But the Persian kingdom, Asia as far as the Indus, he conquered, brought permanently under Macedonian rule, and laid the foundation for its Hellenisation. With this, however, only the smaller portion of his mission was fulfilled. The East everywhere offered further tasks which had in part been undertaken by the Persian kingdom at the height of its power under Darius I--the exploration of Arabia, of the Indian Ocean, and of the Caspian Sea, the subjugation of the predatory nomads of the great steppe that extends from the Danube through southern Russia and Turania as far as the Jaxartes. It was of far more importance that Hellenism had a task in the West like that in the East; to save the Greeks of Italy and Sicily, to overcome the Carthaginians and the tribes of Italy, to turn the whole Mediterranean into a Greek sea, was just as urgently necessary as the conquest of Western Asia. It was the aim that Alcibiades had set himself and on which Athens had gone to wreck. In the same years in which the Macedonian king was conquering the Persians, his brother-in-law, Alexander of Epirus, at the request of Tarentum, had devoted himself to this task. After some success at the beginning he had been overcome by the Lucanians and Bruttians and the opposition of Hellenic particularism (334-331 B.C.).