a. The Underlying Unity:
The study of Indian history normally begins with the assertion of fundamental unity of India.The reason behind is that apparent diversities of India are so palpable as to receive the attention of the students of Indian history first.
Some of the modern historians have also opined that the racial diversity in India is a reality, and the idea of unity mere imagination. But one can put forward a good number of examples to prove the futility of the statement.
First, since the days of Aryan migration, various races of people came to India in different periods of history. Moreover, in India itself a number of religious ideas were initiated and different alien religions spread.
In spite of all these racial and religious diversities the Indian people are accustomed to a common life-style. In fact, it is this general characteristic of the Indian life-style that proclaims the inherent unity of India.
Second, some people are of the opinion that the political unity of India is rather a recent development. But numerous examples may be cited to prove that from the ancient days there have been attempts to represent the political unity of the country.
The ancient poets and philosophers of India have always meant the whole of India when they referred to Bharatavarsha. Moreover, the title Chakravartin was assumed only by those emperors who had spread their empire from the north to the south of India.
b. Unity of Language:
Another unifying influence was supplied by the Sanskrit language.
In fact, the basis of most of the spoken and written languages of modern India was formed in ancient India.
The idea of unity was expressed in the Post-Gupta period when Sanskrit came to be recognized as the national language.
Further, Sanskrit vernaculars, notably Hindustani, are spoken or understood by the majority of the people of northern India and a considerable section of the people of the Deccan.