Orkhon / Old Turkic  

The earliest known examples of writing in any Turkic language were
found in the Orkhon river valley in Mongolia in the 19th century. They
date from the early 8th century AD and the script in which they are
written is known as the Orkhon alphabet, or the Old Turkic script, the
Göktürk script, or the Orkhon-Yenisey script. Inscriptions dating from the
later 8th century AD in a slight variant of the Orkhon alphabet, known
as Yenisei or Siberian runes, have also been found around Yenisei and
other parts of Siberia.

Because of a superficial resemblance to the Runic
alphabet, the alphabet is also known as Orkhon or Turkic runes.
This resemblance is probably a result of the writing materials used
– most inscriptions are in hard surfaces, such as stone or wood, and
curved lines are difficult to inscribe in such surfaces.

The Orkhon alphabet is thought to have been derived from or inspired
by a non-cursive version of the Sogdian script. By the 9th century AD,
the Orkhon and Yenisei alphabets were replaced by the Uighur alphabet,
which developed from the cursive version of the Sogdian script.

Notable features

• Type of writing system: alphabet
• Direction of writing: written mainly from right to left in horizontal
  lines, though some inscriptions are written vertically with the letters
  rotated by 90°. When written vertically, it read from bottom to top
  and right to left.
• Some consonants have two forms, one of which was used with front
  vowels, the other with back vowels.
• Used to write: Old Turkic (a.k.a. East Old Turkic, Orkhon Turkic, Old Uyghur),
  the earliest attested form of Turkic, found in Göktürk and Old Uyghur
  inscriptions dating from between the 7th and 13th century.

Orkhon/Old Turkic alphabet

Sample text

Transliteration

Türk Oguz begleri, bodun, eşidin üze Tengri basmasar
asra yir telinmeser Türk bodun ilinin, törüngün
kim artatı udaçı erti?

A recording of this text by Görkem

Modern Turkish version

Türk Oğuz beyleri, kavmi, işitin; üstte
gök (Tanrı) bastırmasa, altta yer delinmese
Türk kavmi; ilini, töreni kim bozabilirdi?

English version

Türk Oguz chieftains, clans, listen; unless the sky (Sky is
also God) crushes, the ground punctures Turk clans; who could ever
destroy your land and law?

Links

Information about the Orkhon alphabet and Old Turkic language
http://en.wikipedia.org/wiki/Old_Turkic_script
http://gokbeyuluc.wordpress.com
http://fankibiber.wordpress.com/
http://kokturukce.blogspot.com/2008/09/gktrk-yazlarnn-harflerinin-kkeni-4.html
http://www.gokturkce.net
http://irq.kaznpu.kz/?lang=e&mod=1

Details of ancient Turkic languages and alphabets (in English and Russian)
http://www.turkicworld.org

Orkhon font
http://m10lmac.blogspot.com/2010/03/typing-orkhonold-turkic.html

Speculations on connections between Turkic runes and other runic alphabets
http://www.antalya-ws.com/futhark/FUTHP2E.HTM