Syriac alphabet, writing system used by the Syriac Christians from the 1st century ad until about the 14th century. A Semitic alphabet, Syriac was an offshoot of a cursive Aramaic script. It had 22 letters, all representing consonants, and was generally written from right to left, although occasionally vertically downward. Diacritical marks to represent vowels were introduced in the 8th century; two systems of vocalization were developed, one similar to the system in Arabic, and one using small Greek letters above or below the line.
There were several varieties of Syriac script; the oldest of these was Estrangela, or Estrangelo, which was in almost exclusive use until about 500. A schism in the Syriac church at the Council of Ephesus (431) resulted in the division of the Syriac language and script into two forms, western and eastern. The western variety nearly died out under Muslim Arabic domination after the 7th century, but scattered communities of Syriac Christians survived, some of which continued to use the Syriac script. Documents of the Melchite sect of Palestinian Syrians date from as late as the 14th century. The eastern, or Nestorian, script remained in use in Central Asia and Siberia until the 13th or 14th century, as attested by inscriptions on gravestones in southern Siberia. The earliest extant Syriac inscription dates from about ad 50.