ALEXANDER AT BABYLON, SUSA, AND PERSEPOLIS.--From the field of Arbela Alexander marched south to Babylon, which opened its gates to him without opposition. Susa was next entered by the conqueror. Here he seized incredible quantities of gold and silver ($57,000,000, it is said), the treasure of the Great King. From Susa Alexander's march was next directed to Persepolis, where he secured a treasure more than twice as great ($138,000,000) as that found at Susa. Upon Persepolis Alexander wreaked vengeance, for all Greece had suffered at the hands of the Persians. Many of the inhabitants were massacred, and others sold into slavery; while the palaces of the Persian kings were given to the flames. Alexander, having thus overthrown the power of Darius, now began to regard himself, not only as his conqueror, but as his successor, and was thus looked upon by the Persians, He assumed the pomp and state of an Oriental monarch, and required the most obsequious homage from all who approached him. His Greek and Macedonian companions, unused to paying such servile adulation to their king, were much displeased at Alexander's conduct, and from this time on to his death, intrigues and conspiracies were being constantly formed among them against his power and life. CONQUEST OF BACTRIA.--Urged on by an uncontrollable desire to possess himself of the most remote countries of which any accounts had ever reached him, Alexander now led his army to the north, and, after subduing many tribes that dwelt about the Caspian Sea, boldly conducted his soldiers over the snowy passes of the Hindu Kush, and descended into the fair provinces of Bactria. During the years 329-328 B.C. Alexander conquered not only Bactria but Sogdiana, a country lying north of the Oxus. Among his captives here was a beautiful Bactrian princess, Roxana by name, who became his bride. Alexander's stay in Sogdiana was saddened by his murder of his dearest friend Clitus, who had saved his life at the Granicus. Both were flushed with wine when the quarrel arose; after the deed, Alexander was overwhelmed with remorse. CONQUESTS IN INDIA.--With the countries north of the Hindu Kush subdued and settled, Alexander recrossed the mountains, and led his army down upon the rich and crowded plains of India (327 B.C.). Here again he showed himself invincible, and received the submission of many of the native princes. The most formidable resistance encountered by the Macedonians was offered by a strong and wealthy king named Porus. Captured at last and brought into the presence of Alexander, his proud answer to the conqueror's question as to how he thought he ought to be treated was, "Like a king." The impulsive Alexander gave him back his kingdom, to be held, however, subject to the Macedonian crown.