The Old Aramaic language was adopted by the Neo-Assyrian Empire (911–605 BC) when the Assyrians conquered the various Syro-Hittite states to its west. The Achaemenid Empire (546-332 BC), which rose after the fall of the Assyrian Empire, also retained Old Aramaic as its official language, and Old Aramaic remained the lingua franca of the region. During the course of the third and fourth centuries AD, the inhabitants of the region began to embrace Christianity.
Along with Latin and Greek, Syriac became one of "the three most important Christian languages in the early centuries" of the Common Era. From the 1st century AD, Syriac became the vehicle of Syriac Christianity and culture, and the liturgical language of the Syriac Orthodox Church and subsequently the Assyrian Church of the East, along with its descendants: Chaldean Catholic Church, the Ancient Church of the East, the Malankara Orthodox Syrian Church, and the Assyrian Pentecostal Church.
Syriac Christianity and language spread throughout Asia as far as the Indian Malabar Coast and Eastern China, and was the medium of communication and cultural dissemination for the later Arabs and, to a lesser extent, the Parthian Empire and Sasanian Empire. Primarily a Christian medium of expression, Syriac had a fundamental cultural and literary influence on the development of Arabic, which largely replaced it towards the 14th century. Syriac remains the sacred language of Syriac Christianity to this day.
Syriac was the local accent of Aramaic in Edessa, that evolved under the influence of Church of the East and Syriac Orthodox Church into its current form. Before Arabic became the dominant language, Syriac was a major language among Christian communities in the Middle East, Central Asia and Kerala, and remains so among the Syriac Christians to this day. It has been found as far afield as Hadrian's Wall in Great Britain, with inscriptions written by Assyrian and Aramean soldiers of the Roman Empire.