India's extraordinary history and geography are inextricably interrelated. A meeting ground between the East and West, it was routinely invaded, while at the same time its natural isolation and magnetic religions allowed it to adapt to and absorb many of the peoples who penetrated its mountain passes.

Regardless of the many Persians, Greeks, Chinese nomads, Arabs, Portuguese, British and other raiders who conquered the land, local Hindu kingdoms invariably survived their depradations, living out their own sagas of conquest and collapse. All the while, these local dynasties built upon the roots of a culture well established since the time of the first invaders, the Aryans. In short, India has always been simply too big, too complicated, and too culturally subtle to let any one empire dominate it for long.

The first group to invade India were the Aryans, who came out of the north in about 1500 BC, and brought with them strong cultural traditions that, miraculously, remain today. They spoke and wrote in a language called Sanskrit, which was later used in the first documentation of the Vedas. Though warriors and conquerors, the Aryans lived alongside Indus, introducing them to the caste system and establishing the basis of the Indian religions.

Later, the Persians and Greeks subdued the Indus Valley and the northwest, while Aryan-based kingdoms continued developing in the East. In the 5th century BC, Siddhartha Gautama founded the religion of Buddhism, a profoundly influential work of human thought still espoused by much of the world.