Matthew of Edessa was an Armenian historian of the 12th century born in the city of Edessa. (11th century - 12th century - 13th century - other centuries) As a means of recording the passage of time, the 12th century was that century which lasted from 1101 to 1200. ... Edessa is the historical name of a town in northern Mesopotamia. ...
Among the illustrious disciples of the School of Edessa special mention is due to Bardesanes (154-222), a schoolfellow of Abgar IX, the originator of Christian religious poetry, whose teaching was continued by his son Harmonius and his disciples.
In the meanwhile Christian priests from Edessa had evangelized Eastern Mesopotamia and Persia, and established the first Churches in the kingdom of the Sassanides.
It was retaken by the Arabs, and then successivelly held by the Greeks, the Seljuk Turks (1087), the Crusaders (1099), who established there the "county" of Edessa and kept the city till 1144, when it was again captured by the Turk Zengui, and most of its inhabitants were slaughtered together with the Latin archbishop.
The Kingdom of Jerusalem included three significant feudal dependencies: the County of Edessa (1098-1144), the Principality of Antioch (1098-1268), and the County of Tripoli (1109-1289).
The eastern border of Edessa is shown at the Tigris River, but the County may not have extended quite that far.
The fall of Edessa in 1144 was the first major setback for Outremer and provoked the Second Crusade.