The second major civilization in India, approximately 1500 BC - 500 BC.
For several hundred years after the decline of the Indus civilization life in Indian was structured around small villages. A second period of urbanization, known as the Ganges civilization, began about 1500 BC.
Shortly before that time a nomadic people, the Aryans, entered India from the Iranian region. Being cattle herders, the Aryans learned to make use of the fertile river valleys from the remaining Harappans and settled down, either mingling with and absorbing the Harappans or making them subservient to them.
The arrival of the Aryans coincided with the introduction of Vedic, an early form of Sanskrit, the first Indian script. The earliest examples of Indian literature, the Vedas, originate from this time, and the Ganges civilization is therefore often called the Vedic period.
Sanskrit syntax and vocabulary has many similarities with Greek and Latin and is believed to belong to the Indo-European languages. There is no doubt that unlike the people of the Indus civilization, the Aryans were not descendants of local people. Whether they subjugated the darker skinned Indus peasants or not is not clear, but their arrival coincides with the introduction of the caste system, which finds some degree of justification in the Aryan Vedas.
A wealth of literature from the Vedic period gives some idea about the social organization of the time. During the first centuries of the Ganges civilization the dominant activity remained cattle-breeding, and cattle was the main commodity. Family communities relied on each other as clans, which frequently went to war over cattle ownership. (The Sanskrit word for "war", gavisti, literally means "searching for cows".) Much of the literature of the period recounts the names of clans and their achievements. The names of the most powerful clans survived into the present as the names of geographical regions in India.
Towards the end of the Ganges civilization period the clans had settled permanently and staked out their territies. Clan identification was replaced by identification with a territory, and the major clans developed into kingdoms.