Until the discovery of the Indus Valley Civilization in 1920, ancient India seemingly had two main scripts in which languages were written, Brahmi and Kharosti. The Brahmi script developed under Semitic influence around 7th c. BC, and was originally written from right to left. The Kharosti script came into being during the 5th c. BC in northwest India which was under Persian rule.
Although the origin of the Brahmi script is uncertain, the Kharosti script is commonly accepted as a direct descendant from the Aramaic alphabet. The direction of writing in the Kharosti script is as in Aramaic, from right to left, and there is also a likeness of many signs having similar phonetic value.
In the later centuries of its existence, Brahmi gave rise to eight varieties of scripts. Three of them - the early and late Mauryas and the Sunga - became the prototypes of the scripts in northern India in the 1st c. BC and AD. Out of these developed the Gupta writing which was employed from the 4th to the 6th c. AD.
The Siddhamatrka script developed during the 6th c. AD from the western branch of the eastern Gupta character. The Siddhamatrka became the ancestor of the Nagari script which is used for Sanskrit today. The Nagari developed in the 7th to 9th c. AD, and has remained, since the 7th to 9th centuries, essentially unaltered.
However, certain other factors need to be considered to get the complete picture of script development in India. In 1920 archaeologists announced the discovery of extensive urban ruins in the Indus Valley which pre-dated the earliest literary sources and which caused scholars working on ancient texts to re-examine their views on the different phases of Indian culture. The Rig Veda which speaks in such derogatory terms of the enemies subdued by the Aryan tribes, gives the impression that they were all savage barbarians. The Brahmins for centuries have degraded the original inhabitants of India with the intention of self elevation, preservation and oppression. These ancient dwellers in India were Dravidian, and in fact, their culture had developed a highly sophisticated way of life which compares favorably with that of contemporary urban civilizations in Egypt and Mesopotamia.
The extensive excavations carried out at the two principal city sites, Harappa and Mohenjo-Daro, both situated in the Indus basin, indicates that this Dravidian culture was well established by about 2500 B.C., and subsequent discoveries have revealed that it covered most of the Lower Indus Valley. What we know of this ancient civilization is derived almost exclusively from archaeological data since every attempt to decipher the script used by these people has failed so far. Recent analyses of the order of the signs on the inscriptions have led several scholars to the view that the language is not of the Indo-European family, nor is it close to the Sumerians, Hurrians, or Elamite, nor can it be related to the structure of the Munda languages of modern India. If it is related to any modern language family it appears to be Dravidian akin to Old Tamil, presently spoken throughout the southern part of the Indian Peninsula.
What this points to is the existence of a system of writing far more ancient than what was originally considered. For instance when the Indian scripts are grouped, the southern scripts form a class of their own. The Grantha alphabet, which belongs to the writing system of southern India, developed in the 5th c. AD and was mainly used to write Sanskrit. Inscriptions in Early Grantha, dating from the 5th to 6th c. AD are on copper plates and stone monuments from the kingdom of the Pallavas near Chennai (Madras).
The influx of foreign invaders through the northwest over the centuries, forced the Dravidians, the original inhabitants of India, south. Scholars have indicated that the south has been the gateway for religious and cultural developments in India. Originally Grantha was used for writing Sanskrit only, and Sanskrit was later transliterated with Nagiri after the 7th c. AD. Scholars over the years have indicated that many Hindu writings have been tampered with, and certainly this could have happened during the transliteration process. The later varieties of the Grantha script were used to write a number of Dravidian Languages, and the modern Tamil script certainly seems to be derived from Grantha.
The bibliographical evidences indicate that the Vedas are written in the Grantha and Nagari scripts, and according to tradition Veda Vyasa, a Dravidian, compiled and wrote the Vedas. The Grantha script belongs to the southern group of scripts and Veda Vyasa being a Dravidian would certainly have used it. Since the earliest evidence for Grantha is only in the 5th c. AD, the Vedas were written rather late.
Another important fact is brought out in the account of the religion, philosophy, literature, geography, chronology, astronomy, customs, laws and astrology of India about AD 1030 by Alberuni (edited by Dr. Edward C. Sachau). He states that,
“The Indian scribes are careless, and do not take pains to produce correct and well-collated copies. In consequence, the highest results of the author’s mental development are lost by their negligence, and his book becomes already in the first or second copy so full of faults, that the text appears as something entirely new, which neither a scholar nor one familiar with the subject, whether Hindu or Muslim, could any longer understand. It will sufficiently illustrate the matter if we tell the reader that we have sometimes written down a word from the mouth of Hindus, taking the greatest pains to fix its pronunciation, and that afterwards when we repeated it to them, they had great difficulty in recognising it.”
This is a clear opposite to Yuan Chwang’s time in the 7th c AD, when this young Chinese Buddhist scholar came to India in search of authentic sacred books which he accomplished. However, scholars indicate that the same is not true with early Tamil classics like the Sangam literature (3rd c. BC - 3rd c. AD) which are remarkably helpful in the reconstruction of history (K.K.Pillai, Tamil Literature as Source Material for History - Journal of Institute for Asian Studies).
The first epigraphic evidence of Sanskrit is seen in 150 AD and this inscription is in the Brahmi script.
Extracted from the Encyclopedia Britannica, 1982.