The Harappan civilisation started to decline around 1,750 BC; about the same time Indo-Aryan Nomads were making incursions into the Indus Valley. Aryans were a mainly pastoral tribe from Turkmenistan that was much wetter and more fertile in 2,000 BC than today, so had become agricultural. They brought with them the Sanskrit language that was the precursor to many languages including a number of those of later India and Pakistan, such as Gujurati, Bengali and Urdu. As examples of the subsequent widespread use of Sanskrit, the words patar and matar mean father and mother. Sanskrit is an Indo-Aryan language that is in turn a sub-set of the Indo-European language group, so called as it covers many Indian and European languages as well as languages such as Romany, Persian and Kurdish. The Indo-European name came about when systematic similarities in word forms and meanings indicated that speakers of this language group, that is thought to have originated around the Black Sea, formed a common community before 8,000 BC that broke up as groups migrated. Genetic and linguistic research shows that human races and languages have developed together as a result of tribal social patterns. In tribal societies, interbreeding groups of people develop more or less in isolation, creating their own genetic “library”, speech dialect and eventually language.

A major cause of the Harappan demise was the climate, as it became cooler and drier, possibly leading to the drying up of the ancient Saraswati River that flowed east of the Indus. Another possibility is a geological event, such as an earthquake, altering the course of the river system. Satellite pictures show the site of an ancient dried-out riverbed in line with the Harappan cities. The Indo-Aryans probably took advantage of the collapse to migrate to the Indus Valley rather than actually invading. They absorbed much of the Harappan culture, but also established themselves as the dominant elite (“arya” means nobility or civilised). Because of these changes, the magnificent cities were abandoned and allowed to decay, and the urbanisation of the Indus valley disappeared, with a village culture returning and some of the people probably migrating to the Ganges Plain.

In the aftermath of the collapse of the Harappan civilisation, Regional Cultures developed in Northern India. As an example an ochre-coloured pottery was produced between 1,700 and 1,200 BC that was linked to the Harappan culture, but spread from Rajasthan into the Ganges Plain. Also white painted black and red ware was found in Rajasthan dated to 1,500 BC. Cremation also began in the former Harappan Cities, a practice dominant in Hinduism until today. These illustrate the overlap and transfer between the various cultures, and many elements of Harappan Culture can be found in later cultures.

From about 1,500 BC a new Indo-Aryan culture became apparent in India, which lasted until 500 BC. This is known as the Vedic Culture and was characterised by a new language and rituals, and the use of horses and two-wheeled chariots. It was also a major influence in the development of the three major Indian religions. Hinduism is considered to be the oldest extant religion. It was derived as a conglomerate of the diverse beliefs and traditions in the Indus Valley between 5,500 and 3,300 BC, and became crystallised in the Vedic civilisation. It spread over much of India before the rise of Jainism or Buddhism. Although Jainism has no known founder, Mahavira Jayanti is regarded as giving it its present-day form around 600 to 550 BC. He was a prince who renounced worldly pleasures. Siddhartha Guatama, who was a spiritual teacher and became the first Buddha of our age, founded Buddhism. He probably lived from 560 to 480 BC. Buddhism too is one of the oldest religions practiced today. All these three religions were based on non-violence, meditation and relinquishing worldly goods.