The Vedic texts were passed down by oral tradition. It is estimated that Rig Veda, the oldest of the Vedas, was composed sometime between 1700 BC and 1100 BC. The later Vedas - the Sama Veda, Yajur Veda, and Atharva Veda draw heavily from the Rig Veda. The Vendanta texts - the Samhitas and the Upanishads - were commentaries or auxiliary texts dealing with philosophy, theology, sociology, politics, culture, and ethics.
The sacred texts of Vedic India attempted to provide a complete guide to life and religion. From describing the origins of the universe to ascertaining the roles of the various members of society, and from providing commentary on the ethical responsibilities of every individual to determining the rites, rituals, and hymns of worship, the Vedas were treated as the basis of life in Vedic India.
The Vedas laid down a system of classes, and society in Vedic India was organized into Varnas or classes. These were strictly occupational divisions. Marriage rules were, however, rigid, and intermingling was discouraged. In Vedic India the classes were all treated equally and society was patriarchal. Following the collapse of the Vedic period, two Varnas, Brahmins and Kshatriyas, took precedence and the class system turned into a caste system.
As prescribed by the Vedas, the Brahmins were given to intellectual pursuits. They sung hymns and poems in praise of the gods, preserved tradition and the sacred texts, cultivated sciences, and performed rituals. The Kshatriyas functioned as warriors and administrators. The king was a Kshatriya and so was the army. They meted out the law and were responsible for policy making. The Vaishyas were farmers and traders. They formed the economic backbone of Vedic society. The Shudras were artisans, masons, and laborers.
The king (Rajan) would regularly consult representatives of all the Varnas in times of decision making.
The religious tenets as propagated by the Vedas were unique in the sense that they were both monotheistic and polytheistic. A pantheon of gods was worshipped, but each deity was a form of the One Supreme Being (Brahma). The worship of the deities depended on the needs, times, and correspondence. The celestial bodies and the elements were worshipped as gods. The study of Vedic mathematics, astrology, and astronomy were very advanced and tied to the complex religion of the Vedas.