Ancient India

India lies in the valleys of the Indus and Ganges. The warm climate and the fertile silt brought by the rivers favoured farming; the Himalayas served as a natural barrier in the north. In the 3rd millennium BCE large cities such as Mohenjo-daro and Harappa arose in the Indus Valley. They were surrounded by defensive walls, had straight streets, houses of baked and mud brick, and many craftsmen. The people farmed and grew cotton and sugarcane. From about the 19th–18th centuries BCE these cities declined (floods and climate change are among the suggested causes). The Indians worshipped forces of nature: the sun god, Indra the god of thunder, Ganesha the elephant-headed god of wisdom, and the supreme god Brahma. They believed the soul moves from one body to another (rebirth); the cow was sacred. Society was divided into four varnas: Brahmins (priests), Kshatriyas (warriors), Vaishyas (farmers, craftsmen, merchants) and Shudras (servants). A person usually stayed in the varna of his parents, and marriage between varnas was almost forbidden. Those outside any varna (“chandalas”) were looked down on.