Tamil-Brahmi

Tamil-Brahmi, also known as Tamili or Damili, is a variant of the Brahmi script used to write inscriptions in the early form of the Old Tamil language. The Tamil-Brahmi script has been paleographically and stratigraphically dated between the 3rd century BCE and the 1st century CE, and it constitutes the earliest known writing system evidenced in many parts of Tamil Nadu, Kerala, Andhra Pradesh and Sri Lanka. Tamil Brahmi inscriptions have been found on cave entrances, stone beds, potsherds, jar burials, coins, seals, and rings.
Tamil Brahmi resembles but differs in several minor ways from the Brahmi script inscriptions found elsewhere on the Indian subcontinent such as the Ashokan edicts found in Andhra Pradesh. It adds diacritics to several letters for sounds not found in Prakrit, producing "ṉ ṟ ṛ ḷ". Secondly, in many of the inscriptions the inherent vowel has been discarded: A consonant written without diacritics represents the consonant alone, whereas the Ashokan diacritic for long "ā" is used for both "ā" and short "a" in Tamil Brahmi. This is unique to Tamil Brahmi and Bhattiprolu among the early Indian scripts. Tamil Brahmi does not, however, share the odd forms of letters such as "gh" in Bhattiprolu. This appears to be an adaptation to Dravidian phonotactics, where words commonly end in consonants, as opposed to Prakrit, where this never occurs. According to Mahadevan, in the earliest stages of the script the inherent vowel was either abandoned, as above, or the bare consonant was ambiguous as to whether it implied a short "a" or not. Later stages of Tamil Brahmi returned to the inherent vowel that was the norm in ancient India.
According to Kamil Zvelebil, Tamil-Brahmi script was the parent script that ultimately evolved into the later Vatteluttu and Tamil scripts.
Origins.
Early Tamil scripts.
An early mention of a script for writing the Tamil language is found in the Jaina work "Samavayanga Sutta" and "Pannavana Sutta" where a script called "Damili" is mentioned as the seventeenth of eighteen "Lipi" (scripts) in use in India. Similarly, the tenth chapter of the "Lalitavistara", named "Lipisala samdarshana parivarta", lists Dravida-lipi and Dakshinya-lipi as two of sixty four scripts that Siddhartha (later the Gautam Buddha) learnt as a child from his gurus in Vedic schools, a list that is found in both Indian Buddhist texts and its ancient Chinese translations. These relationship of early Tamil scripts to these "lipi" mentioned in Jaina and Buddhist literature relationship is unclear. The pre-1974 work of Mahadevan had established 76 rock inscriptions in Tamil Brahmi from about 21 sites in Tamil Nadu, which states Kamil Zvelebil "establish obvious correlations" with what has been found in early Tamil bardic poems. Nagaswamy treats Tamil-Brahmi script to be synonymous with the Damili script in his publications.
Artifacts such as inscribed potsherds, coins or others are found in Tamil Nadu archaeological sites have graffiti and inscriptions. The potsherds recovered from Kodumanal, for example, have markings that on the basis of stratigraphical analysis appear to be from the 4th century BCE. According to K. Rajan, the "large number of graffiti marks and subsequent Tamil Brahmi script" unearthed in Tamil Nadu and Kerala suggest that this region had a "linguistic cohesiveness well before 5th-4th century BCE".
Pre 1990s.
The origins and chronology of Tamil Brahmi are unclear. Several hypotheses have been proposed, with the views of epigraphist Iravatham Mahadevan being generally more accepted. According to Mahadevan, the Brahmi script from North India arrived via the southern inscriptions of Ashoka, and evolved into the Tamil Brahmi. This theory presupposes that the Brahmi script itself was either originated within the imperial courts of Mauryan kingdom or evolved from a more ancient foreign script and it was dispersed to South India and Sri Lanka after the 3rd century BCE. The alternate theory proposed by Nagaswamy is that there was an indigenous common source (proto-Vatteluttu) script from which both northern and southern Brahmi script emerged, which he respectively terms as "Brahmi" and "Damili" scripts. Richard Salomon favors the Mahadevan theory. 
According to Kamil Zvelebil's chronology proposal of 1973, the earliest Tamil Brahmi inscriptions such as the Netunceliyan rock inscriptions at the Mangulam site were derived from Ashokan Brahmi that was introduced to the Tamil region around 250 BCE. It was adapted for the Tamil language by 220 BCE and led to the standardization of the Tamil language and literary norms of Maturai between 200 and 50 BCE. These developments transformed the oral bardic Tamil literary culture to the written Sangam literature in the centuries that followed. The use of Tamil Brahmi continued through the 6th century CE, states Zvelebil.
Since 1990s.
Since the 1990s, pre-Ashokan dates have been proposed based on excavations and discoveries of graphite covered ancient remains in Sri Lanka. These include those found in Anuradhapura in Sri Lanka, some of which have been dated to the 4th century BCE. The findings of Coningham et al based on the carbon dating of excavated potsherds led to the proposal that the Sri Lankan Brahmi developed before Ashokan era, at least by the 5th to 4th century BCE, from where it came to Tamil region evolving into the Tamil Brahmi, and thereafter spread across South Asia due to trade networks. Sri Lankan nationalists have used this and other fragments of Black-and-Red Ware and Red Ware with Brahmi characters to state that Brahmi was invented on the island and from there it migrated north into the Indian subcontinent. This theory has been criticized by Harry Falk – a scholar of Brahmi and other ancient Indian scripts. First, states Falk, the Coningham team has admitted later that they did not use the carbon dating correction necessary for the Southern hemisphere and used the calibration curves for north Pakistan. Second, the Sri Lankan teams also erred when they deployed a "mathematical trick" whereby they conflated the contested date of lower strata that lacked inscribed shreds with the upper strata where the shreds with Brahmi script were found. According to Falk, a critical study of the feature differences between Ceylonese (Sri Lankan) Brahmi, Tamil Brahmi and Ashokan Brahmi suggest that "all the differences can only be explained once the Ashokan script is taken as primary and the two others as derivations". It is not scholarship that is behind the claims that Ceylonese Brahmi is more ancient and gave rise to Tamil Brahmi and Ashokan Brahmi, rather it is "regional chauvinism", states Falk.
The graffiti and Brahmi found at sites in Sri Lanka are related, but not considered to be examples of Tamil-Brahmi. 
Archaeological teams sponsored by the government of Tamil Nadu have also been actively unearthing sites and reporting their results in local media that they have found shreds and items with Tamil Brahmi inscriptions. Between 2011 and 2013 for example, Rajan and Yatheeskumar published their findings from excavations at Porunthal and Kodumanal in Tamil Nadu, where numerous graffiti and inscription fragments on archaeological pieces have been unearthed. The radiocarbon dates of paddy grains and charcoal samples found along with potsherds with inscriptions provided a radiometric date of about 520–490 BCE, which state Rajan and Yatheeskumar implies that the inscriptions too are from the same period. Based on Carbon-14 dating by an American
laboratory, Rajan suggests Tamil Brahmi had been invented by 490 BCE, and states, "it is almost clear now that Ashoka did not the Brahmi script. The origin or evolution of a script is a social process and it could not be associated with a particular individual or dynasty." Responding to Rajan's findings, Harry Falk, wrote that the earliest supposed inscriptions are not Brahmi letters at all, but misinterpreted Megalithic graffiti symbols, which were used in South India for several centuries during the pre-literate era. The stirrups reportedly found with the shreds are suspicious. Falk considers these reports as "regional chauvinism" just like the Sri Lankan claims of their island being the origin of Brahmi script development. According to linguist David Shulman if these early dates are correct then the transition to proto History needs to be pushed backed to fourth or even fifth century BCE, but he concurs there are reasons to be bit skeptical of pre-Ashokan dates for Tamil-Brahmi, but recommends that one should keep an open mind.
The script.
Tamil-Brahmi had notable peculiarities when compared to the Standard Brahmi. It had four different characters to represent Dravidian language phonemes not represented in the standard northern-based Brahmi used to write Prakrit languages. The closest resemblance to Tamil-Brahmi is to its neighboring Sinhala-Brahmi. Both seem to use similar letters to indicate phonemes that are unique to Dravidian languages although Sinhala-Brahmi was used to write an Indo-Aryan Prakrit used in the island of Sri Lanka possibly from ongoing maritime relationship with Gujarat and other parts of India.
The Tamil Brahmi script found in ancient Tamil inscriptions is not consistent. It appears to have existed in three different versions between the 2nd century BCE and 3rd century CE. The third version, assumed to be the basis for early "Tolkāppiyam", evolved into the modern Tamil script.
The Bhattiprolu script is related to the Tamil-Brahmi, and is found in nine early inscriptions on stupa relic caskets discovered at Bhattiprolu (Andhra Pradesh). According to Richard Salomon, the Bhattiprolu script reflects innovations in a Dravidian language context, rather than Indo-Aryan languages. Both the Bhattiprolu and Tamil Brahmi share common modifications to represent Dravidian languages. The Bhattiprolu was likely a provincial offshoot of early southern Brahmi script, states Salomon. 
According to Iravatham Mahathevan there are three stages in the development of the script. The early stage is dated from the 3rd or 2nd century BCE to 1st century BCE. The later stage is dated from the 1st to 2nd century CE. The third stage is dated from the 2nd century CE to the 3rd or 4th century CE. According to Gift Siromony, the types of Tamil Brahmi writings do not follow a very clear chronology and can lead to confusion in dating. According to K. Rajan, the Ashokan Brahmi corresponds with the Stage II of Tamil Brahmi per Mahadevan’s classification. Hence according to him, Stage I may have to be reassessed from the proposed time line. From the 5th century CE onwards Tamil is written in Vatteluttu in the Chera and Pandya country and Grantha or Tamil script in the Chola and Pallava country. Tamil Brahmi inscriptions in cave beds and coins have provided historians with identifying some kings and chiefs mentioned in the Sangam Tamil corpus as well as related Ashokan pillar inscriptions.
Usage.
The Tamil Brahmi script inscriptions are predominantly found with ancient Tamil Jaina and Buddhist sites, states Zvelebil. According to Ranjan, all the Tamil-Brahmi inscriptions found in rock caves of Tamil Nadu are related to Jainism. The Tamil-Brahmi inscriptions are also found in secular context such as coins, potsherds and others. According to Zvelebil, its origins likely were with the Jains and the Buddhists, but it was soon understood and used by kings, chiefs, potters and other common people from a variety of backgrounds. This is evidenced by the use of a fused Tamil and Prakrit languages in the secular inscriptions.
According to Rajan, certain graffiti marks may imply that the script was used for funerary and other purposes. The language used in most of the religious inscriptions show Prakrit elements and influence. Cave and rock bed Tamil Brahmi inscriptions, as well as those found near Madurai, are typically donatory and dedicated resting places and resources for monks. Other major usages of Tamil Brahmi inscriptions are similar to those found in Andhra Pradesh, such as in coins and those that mention merchants and traders of gold, sugar, iron, salt and textiles. Some Tamil Brahmi inscriptions mention the names of ancient kings, heroes, and places. This has served as an important and a more reliable means to date Tamil literature and history from about the 3rd century BCE and thereafter.
A significant archaeological source of Tamil Brahmi inscriptions has been the region between Palghat gap and Coimbatore along the Kaveri river and to its delta. The excavations here revealed nearly two hundred inscribed potsherds along with items relating to iron-smelting and jewelry manufacturing. These inscribed potsherds contain a mix of ancient Indian languages – mostly in early Tamil in Tamil Brahmi, and some in Prakrit languages in Brahmi. These are dated to about 300 to 200 BCE by archaeo-magnetic analysis. They suggest an economic vibrancy, trade and cultural exchange between ancient Tamil region and other parts of India. A similar mix of Tamil Brahmi and Brahmi script is found in shards, potsherds and rock inscriptions all along the coast of the Bay of Bengal, from Salihundam in northeast Andhra Pradesh to ancient near-coast settlements of Tamil Nadu such as those near Vaddamanu, Amaravati, Arikamedu, Kanchipuram, Vallam, Alagankulam and Korkai. 
Discoveries at Kodumanal near Coimbatore have unearthed potsherds with Tamil Brahmi inscriptions dated 300 to 200 BCE. These include names mostly in Tamil language (Kannan Atan, Pannan), as well as some in Sanskrit (Varuni, Visaki). According to Mahadevan, this admixture of a few loan words of north Indian languages written in northern Brahmi with those in Tamil Brahmi is neither abnormal nor exception in the epigraphical evidence discovered in Tamil Nadu. This trend continued in centuries that followed where Tamils inscribed Sanskrit words in the Grantha script. According to Vimala Begley, the recent sherds graffiti discoveries in archaeological sites along the coast of Tamil Nadu such as Arikamedu are a mix of Tamil Brahmi, northern Brahmi and Ceylon-Brahmi scripts, and they inscribe both Tamil and Prakrit languages of India. This likely suggests that ancient Tamil Nadu served as one of the important trade staging regions for the Indian subcontinent and beyond.
Decipherment.
A. C. Burnell (1874), attempted the earliest work on South Indian paleography, but it was due to the efforts of K. V. Subrahmanya Aiyar (1924), H. Krishna Sastri and K. K. Pillay that it was understood to be written in an early form of Tamil, not Prakrit. The early attempts assumed more Prakrit loan words than what was actually used, hence the decipherment was not entirely successful. Iravatham Mahadevan identified the writings as mostly consisting of Tamil words in the late 1960s and published them in seminars and proceedings. This was further expanded by T. V. Mahalingam (1967), R. Nagaswamy (1972), R. Panneerselvam (1972) and M. S. Venkataswamy (1981).