Inscriptions constitute the most reliable source of our knowledge of the ancient Indian history. The study of inscriptions is called Epigraphy. Being engraved on stone slabs, pillars, rocks, copper plates, walls of buildings etc. inscriptions are neither easily perishable nor can they be easily tampered with. Majority of inscriptions are commemorative, dedicatory or donative. They commemorate some particular event, public or private, or record the dedication of some buildings or images, or bear testimony to grants of land. Although the correct and definite dates are not always mentioned, yet the changing character of the script enables us to determine the approximate age of the inscriptions. The script also indicates the language known in those days. They are written in different languages, such as Pali, Prakrit, Sanskrit, Tamil, Telegu etc. Before the Gupta period most of the inscriptions were written in Prakrit. Two types of scripts were prevalent in writing these inscriptions viz., Brahmi and Kharosthi. Most of the inscriptions were written in Brahmi, while only a few were written in Kharosthi which was derived from Aramaic and similar to the Semitic alphabet.
The series of deciphered Indian inscriptions open with the edicts of the great Mauryan emperor Ashoka. These edicts are royal commands for regulating social, religious and administrative behaviour. The edicts of Ashoka on rocks and pillars not only tell us about his law of piety but also enable us to form an idea of the extent of his empire. From the Ashokan inscriptions we come to know about Ashoka’s religious policy (Dhamma), administrative system, personal character, advancement and standards of educational system, the ancient language and Ashoka’s relations with other countries. Moreover they also throw light on Mauryan art. These written records which are mostly in the Prakrit language, were engraved in Brahmi script barring a few in the north-west which were engraved in Kharoshthi script written from right to left.
The post-Mauryan and Gupta inscriptions fall into two categories – official and private. The official inscriptions generally record the royal achievements and are written by court poets. Among such inscriptions, popularly known as the Prashastis, the most prominent ones are the Prashasti of the emperor Samudra Gupta engaved on the Ashokan pillar at Allahbad, the Hathigumpha prashasti of king Kharavela of Kalinga, the Nasik inscription of king Gautami Balsree, the Girnar inscription of king Rudradaman, the Aihole inscription of the Chalukya king Pulkesin II, the Bhitri and Nasik inscriptions of the Gupta ruler Skandagupta.
The inscriptions engraved on the copper-plates are available in large numbers. They contain an account of land-grants made by different rulers. These inscriptions describe the area of land granted and also the date of the grant. Some of them also describe the achievements of the rulers who granted lands. These inscriptions, besides many more, of private individuals or local officers, have furnished us with names of various kings, boundaries of their kingdoms and sometimes useful dates and clues to many important events of past.
Private inscriptions are more numerous than the official ones. They are mostly engraved in temples or on images of stones or metals. These have provided us information concerning dates of construction of temples, the development of architecture and sculpture at various places during different times and also the growth of regional languages. Thus, these inscriptions have been of great help in tracing the evolution of art and religion and also in determining the general conditions in any specific period.
The history of Satavahana rulers has been based mostly on their inscriptions. Similarly, the inscriptions of the south Indian rulers like the Pallavas, the Chalukyas, the Rashtrakutas, the Cholas and the Pandyas have been of great help in finding historical facts of the rule of their respective dynasties. Certain inscriptions found outside India throw valuable light on the relations of India with foreign countries. Ashokan inscriptions clearly indicate that he sent his religious preachers to Burma, Ceylon, the Himalayan Terrai, Egypt, Syria, Macedonia, Greece etc.