The Sogdian alphabet was originally used for the Sogdian language, a language in the Iranian family used by the people of Sogdia. The alphabet is derived from Syriac, a descendant script of the Aramaic alphabet. The Sogdian alphabet is one of three scripts used to write the Sogdian language, the others being the Manichaean alphabet and the Syriac alphabet. It was used throughout Central Asia, from the edge of Iran in the west, to China in the east, from approximately 100–1200 A.D. Structure Like the writing systems from which it is descended, the Sogdian writing system can be described as an abjad, but it also displays tendencies towards an alphabet. The script consists of 17 consonants, many of which have alternative forms for initial, middle, and final position. As in the Aramaic alphabet, long vowels were commonly written with matres lectionis, the consonants aleph, yodh and waw. However, unlike Aramaic and most abjads, these consonant signs would also sometimes serve to express the short vowels (which could also sometimes be left unexpressed as in the parent systems). To disambiguate long vowels from short ones, an additional aleph could be written before the sign denoting the long vowel. The alphabet also includes several diacritics, which were used inconsistently. It is written from right to left, but by the time it had evolved into its child system, the Old Uyghur alphabet, it had been rotated 90 degrees, written vertically in columns from left to right. Voiced and voiceless fricatives are consistently not distinguished in the script. Aramaic logograms also appear in the script, remnants of adapting the Aramaic alphabet to the Sogdian language. These logograms are used mainly for functional words such as pronouns, articles, prepositions, and conjunctions. Alphabetisation The Sogdian alphabet was found inscribed in Panjakent, so we can suppose alphabetisation rules - they are the same as in the Aramaic alphabet, but the letter Lāmadh is repeated at the end of the alphabet for values ð, θ. * those letters are not used in Sogdian words. Varieties Three main varieties of the Sogdian alphabet developed over time: Early Sogdian, a Hindu-Buddhist archaic non-cursive type; the sutra script, a calligraphic script used in Sogdian Buddhist scriptures; and the so-called "Uyghur" cursive script (not to be confused with the Old Uyghur alphabet). Early Sogdian dates to the early fourth century C.E., and is characterized by distinct, separated graphemes. The sutra script appears