in a centuries-long process having begun in the Arab conquests. The differences with the Church of the East led to the bitter Nestorian schism in the Syriac-speaking world. As a result of the schism as well as being split between living in the Byzantine Empire in the west and the Sasanian Empire in the east, Syrian-Aramaic developed distinctive Western and Eastern varieties. Although remaining a single language with a high level of comprehension between the varieties, the two employ distinctive variations in pronunciation and writing systems and, to a lesser degree, in vocabulary and grammar. During the course of the third and fourth centuries, the inhabitants of the region began to embrace Christianity. Because of theological differences, Syriac-speaking Christians bifurcated during the fifth century into the Church of the East, or East Syriac Rite, under the Sasanian Empire, and the Syriac Orthodox, or West Syriac Rite, under the Byzantine Empire. After this separation, the two groups developed distinct dialects differing primarily in the pronunciation and written symbolisation of vowels. The Mongol invasions of the Levant in the 13th century and the religiously motivated massacres of Assyrians by Timur further contributed to the rapid decline of the language. In many places outside of northern Mesopotamia, even in liturgy, the language was replaced by Arabic. "Modern Syriac-Aramaic" is a term occasionally used to refer to the modern Neo-Aramaic languages spoken by Christians, including Suret. Even if they cannot be positively identified as the direct descendants of attested Middle Syriac, they must have developed from closely related dialects belonging to the same branch of Aramaic, and the varieties spoken in Christian communities have long co-existed with and been influenced by Middle Syriac as a liturgical and literary language. Moreover, the name "Syriac", when used with no qualification, generally refers to one specific dialect of Middle Aramaic but not to Old Aramaic or to the various present-day Eastern and Central Neo-Aramaic languages descended from it or from close relatives. In 2004, the Constitution of the Iraqi Kurdistan Region recognized Syriac in article 7, section four, stating, "Syriac shall be the language of education and culture for those who speak it in addition to the Kurdish language." In 2005, the Constitution of Iraq recognised it as one of the "official languages in the administrative units in which they constitute density of population" in article 4, section four. Script History The original Mesopotamian writing system, believed