Old Turkic script

The Old Turkic script (also known as variously Göktürk script, Orkhon script, Orkhon-Yenisey script, Turkic runes) was the alphabet used by the Göktürks and other early Turkic khanates from the 8th to 10th centuries to record the Old Turkic language.
The script is named after the Orkhon Valley in Mongolia where early 8th-century inscriptions were discovered in an 1889 expedition by Nikolai Yadrintsev. These Orkhon inscriptions were published by Vasily Radlov and deciphered by the Danish philologist Vilhelm Thomsen in 1893.
This writing system was later used within the Uyghur Khaganate. Additionally, a Yenisei variant is known from 9th-century Yenisei Kirghiz inscriptions, and it has likely cousins in the Talas Valley of Turkestan and the Old Hungarian alphabet of the 10th century. Words were usually written from right to left.
Origins.
According to some sources, Orkhon script is derived from variants of the Aramaic alphabet, in particular via the Pahlavi and Sogdian alphabets of Persia, or possibly via Kharosthi used to write Sanskrit ("cf". the inscription at Issyk kurgan).
Vilhelm Thomsen (1893) connected the script to the reports of Chinese account ("Records of the Grand Historian", vol. ) from a 2nd-century BCE Yan renegade and dignitary named Zhonghang Yue (). Yue "taught the Chanyu (rulers of the Xiongnu) to write official letters to the Chinese court on a wooden tablet () 31 cm long, and to use a seal and large-sized folder". The same sources tell that when the Xiongnu noted down something or transmitted a message, they made cuts on a piece of wood ("gemu"). They also mention a "Hu script". At the Noin-Ula burial site and other Hun burial sites in Mongolia and regions north of Lake Baikal, the artifacts displayed over twenty carved characters. Most of these characters are either identical with or very similar to the letters of the Turkic Orkhon script. Turkic inscriptions dating from earlier than the Orkhon inscriptions used about 150 symbols, which may suggest that tamgas first imitated Chinese script and then gradually was refined into an alphabet.
Contemporary Chinese sources conflict as to whether the Turks had a written language by the 6th century. The "Book of Zhou", dating to the 7th century, mentions that the Turks had a written language similar to that of the Sogdians. Two other sources, the "Book of Sui" and the "History of the Northern Dynasties" claim that the Turks did not have a written language. According to István Vásáry, Old Turkic script was invented under the rule of the first khagans and that it was modelled after the Sogdian fashion. Several variants of the script came into being as early as the first half of the 6th century.
Corpus.
The Old Turkic corpus consists of about two hundred inscriptions, plus a number of manuscripts.
The inscriptions, dating from the 7th to 10th century, were discovered in present-day Mongolia (the area of the Second Turkic Khaganate and the Uyghur Khaganate that succeeded it), in the upper Yenisey basin of central-south Siberia, and in smaller numbers, in the Altay mountains and Xinjiang. The texts are mostly epitaphs (official or private), but there are also graffiti and a handful of short inscriptions found on archaeological artifacts, including a number of bronze mirrors.
The website of the Language Committee of Ministry of Culture and Information of the Republic of Kazakhstan lists 54 inscriptions from the Orkhon area, 106 from the Yenisei area, 15 from the Talas area, and 78 from the Altai area. The most famous of the inscriptions are the two monuments (obelisks) which were erected in the Orkhon Valley between 732 and 735 in honor of the Göktürk prince Kül Tigin and his brother the emperor Bilge Kağan. The Tonyukuk inscription, a monument situated somewhat farther east, is slightly earlier, dating to ca. 722. These inscriptions relate in epic language the legendary origins of the Turks, the golden age of their history, their subjugation by the Chinese (Tang-Gokturk wars), and their liberation by Bilge.
The Old Turkic manuscripts, of which there are none earlier than the 9th century, were found in present-day Xinjiang and represent Old Uyghur, a different Turkic dialect from the one represented in the Old Turkic inscriptions in the Orkhon valley and elsewhere. They include Irk Bitig, a 9th-century manuscript book on divination.
Table of characters.
Old Turkic being a synharmonic language, a number of consonant signs are divided into two "synharmonic sets", one for front vowels and the other for back vowels. Such vowels can be taken as intrinsic to the consonant sign, giving the Old Turkic alphabet an aspect of an abugida script. In these cases, it is customary to use superscript numerals ¹ and ² to mark consonant signs used with back and front vowels, respectively. This convention was introduced by Thomsen (1893), and followed by Gabain (1941), Malov (1951) and Tekin (1968).
Consonants.
A colon-like symbol (⁚) is sometimes used as a word separator. In some cases a ring (⸰) is used instead.
A reading example (right to left): transliterated t²ñr²i, this spells the name of the Turkic sky god, Täñri ().
Variants.
Variants of the script were found from Mongolia and Xinjiang in the east to the Balkans in the west. The preserved inscriptions were dated to between the 8th and 10th centuries.
These alphabets are divided into four groups by Kyzlasov (1994) 
The Asiatic group is further divided into three related alphabets:
The Eurasiatic group is further divided into five related alphabets:
A number of alphabets are incompletely collected due to the limitations of the extant inscriptions. Evidence in the study of the Turkic scripts includes Turkic-Chinese bilingual inscriptions, contemporaneous Turkic inscriptions in the Greek alphabet, literal translations into Slavic languages, and paper fragments with Turkic cursive writing from religion, Manichaeism, Buddhist, and legal subjects of the 8th to 10th centuries found in Xinjiang.
Unicode.
The Unicode block for Old Turkic is U+10C00–U+10C4F. It was added to the Unicode standard in October 2009, with the release of version 5.2. It includes separate "Orkhon" and "Yenisei" variants of individual characters.
Since Windows 8 Unicode Old Turkic writing support was added in the Segoe font.