A. Indigenous Literature:
Historical data collected from the sacred literature and other text written in ancient times are an important source of information.
As regard sacred literature mention may be made of the four Vedas, the two great Epics-the Ramayana and the Mahabharata, the Puranas, etc.
Apart from these Hindu sacred literatures, the Jaina and Buddhist texts are also helpful in forming an idea about the political, social and economic condition of India in ancient times.
Besides these, the literature, scientific and philosophical texts composed in Tamil, Pali and Prakrit languages contain numerous historical statements of considerable value.
The Arthashastra, a book on political science ascribed to Kautilya, throws valuable light on the history of the Pre-Maurya and Mauryan political condition of India.
The importance of some biographical sketches written in ancient times also cannot be denied. In this connection mention may be made of Harshacharita, a biography of king Harshavardhana, composed by Banaohatta; Gaudabaho of Bakpati; Mudrarakshasa of Visakhadatta ; Vikramankadevacharita of Bilhana; Ramacharita of Shandhyakarnandi, etc.
The -famous Sanskrit work, the Rajatarangini, written by a Kashmiri scholar, Kalhana, may be regarded as the first historical text of its kind.
Written in 12th century A.D. Rajatarangini deals with the history of Kashmir from the earliest times.
Recently historians attach much importance to the coins as source materials for the reconstruction of ancient Indian history. For the study of coins reveal such information which no other sour does.
For example, the metal or alloy of metals used in the coins give us an idea about the advancement made in metallurgy during the contemporary period.
Coins also throw light on the economic history. Distribution of coins is an indication that the economic activities under a particular king or kings had been extended to the areas.
Again the coins in which names of kings have been mentioned enable us to know about the chronology of a ruling dynasty.
The Kushana kings had circulated different types of coins in which not only the name but also the year of accession has been mentioned.
This has enabled us to fix the dates of various Kushana kings who ruled over India. The coins are also helpful in reconstructing the cultural history of a particular period.
Thus the importance of coins can hardly be minimized.
Inscriptions are an important source of knowledge about ancient India. Inscription may be of different types such as stone, rock, pillar or copper.
The ancient Indian kings often inscribe stone and copper inscriptions to commemorate their victories in battle field or in remembrance of important events of their reign.
Obviously the inscriptions are helpful in forming a clear idea about the socio-religious life of contemporary India.
For example, the pillar and rock inscriptions of Asoka are the most authoritative source of the history of that Maurya Emperor.
Moreover, the victories of Kharvela, the king of Kalinga, king Rudradamana and the Gupta emperor Samudragupt, have been known mostly from the information supplied by their inscriptions.
The Hatigumpha Pillar Inscription of Kharvela and the Allahabad Pillar Inscription composed by Harisena, the court-poet of Samudragupta are full of contemporary historical information Besides, the Aihole Pillar Inscription of Pulakesin II, the Chalukya king, refers to the story how the conquests of Harshavardhana in the Deccan was put at halt by Pulakesin II himself.
Nevertheless, one should be very much careful in using inscriptions as an historical evidence.
Because most of the inscriptions were eulogies of powerful kings. So, the unnecessary exaggeration of their achievements should be kept in mind.