The great Aryan tide had already flowed from the Central Asian highlands into India, but Jutes and Skyths had yet to make that great drift westward which peopled half of Europe with nomadic tribes speaking kindred tongues--a drift which never rested in its westward advance till, as Anglians and Saxons, it had enveloped England and faced its final destiny in an American continent. Assyria had passed by with arts and commerce rather than with arms, and Persia had followed in Assyrian tracks. Both had established colonies half-way to India in the Afghan highlands, Persia with the aid of captive Greeks, and Assyria with people taken from the Syrian land. The list of Assyrian and Persian satrapies included all those lands which we now call the hinterland of India, and which in Alexander's time must have been absolutely Persianized. But beyond the historical evidence which can be collected to prove the early, the constant, traffic which ensued between Mesopotamia, or Asia Minor, and India, after the consolidation of those two great empires, there is the tradition which certain Greek writers (notably Arrian) treat rather scornfully, of the conquest of Upper India by the mythical hero Bacchus. It is never wise to treat any tradition scornfully, and Arrian is himself obliged to admit the difficulty of explaining certain records connected with Alexander's history, without assuming that the tradition was not groundless. Writing of the city of Nysa, Arrian says that "it was built by Dionysos or Bacchus, when he conquered the Indians; but who this Bacchus was, or at what time or from whence he conquered the Indians is hard to determine, whether he was that Theban who from Thebes, or he who from Timolus, a mountain of Lydia, undertook that famous expedition into India is very uncertain." There is a Greek epic poem in hexameter verse, called the "Dionysiaka," or "Bassarika," which tells of the conquest of India by Bacchus, the greatest of all his achievements. The author is Nonnus of Panopolis in Egypt, who wrote about the beginning of the fifth century of our era. Bacchus is said to have received a command from Zeus to turn back the Indians, who had extended their conquests to the Mediterranean, and in the execution of this command he marched through Syria and Assyria. In Assyria he was entertained with magnificent hospitality. Nothing further is said of the route he took to reach India. The first battle which took place in India was on the banks of the Hydaspes, where the Indians were routed. Then followed as an incident in the war the destruction of the Indian fleet in a naval battle, which is instructive. It took the assistance of the goddess of war, Pallas Athene, to bring the campaign to a conclusion, which terminated with the death of the Indian leader Deriades. Here, then, is crystallized in verse the tradition to which Arrian refers, and remembering that we are indebted to two great epics