Chinese raised the Great Wall to protect themselves from invasion. China in antiquity had some foreign trade and came to be known as the Silk Land (Serica), from the silken goods which found a way into the markets of western Asia and Europe. But the country to the ancients was a land of mystery.
India was better known than China, especially its two great rivers, the Indus and the Ganges, which flow to the southwest and southeast respectively, and make this part of the peninsula one of the most fertile territories on the globe. Such a land attracted immigrants.
The region now known as the Punjab, where the Indus receives the waters of five great streams, was settled by Indo-European peoples sometime after 2000 B.C. They also spread over the valley of the Ganges and so brought all northern India under their control.
India did not remain entirely isolated from the rest of Asia. The Punjab was twice conquered by invaders from the West ; by the Persians in the sixth century B.C., and
about two hundred years later by the Greeks.
From this time India began to emerge from obscurity. A considerable commerce existed with Western peoples, by land routes through central Asia and by water routes leading across the Arabian Sea and up the Persian Gulf and the Red Sea.’ Such Indian luxuries as precious stones, ivory, spices, and fine cotton stuffs were thus introduced among Western peoples. India always remained, however, outside the “Circuit of Lands,” (Orbis Terrarum) familiar to the ancient Greeks and Romans.
The smaller of the two grand divisions of Asia is the Near East. It comprises the region between the Black and Caspian seas on the north, the Red Sea, Persian Gulf, and Indian Ocean on the south, the Indus River on the east, and the Nile on the west. The Near East consists of several vegetation belts. The forest belt supported a migratory, hunting folk. The steppe belt formed the home of nomadic, pastoral tribes. As for the semi-deserts and deserts, these were only habitable in oases. Men could settle down and adopt an agricultural life only where they were assured of a constant water supply and enduring sunlight. They found this assurance particularly in the valleys of the Nile and the Tigris-Euphrates rivers.