The Third Perso-Turkic War was the third and final conflict between the Sassanian Empire and the Western Turkic Khaganate. Unlike the previous two wars, it was not fought in Central Asia, but in Transcaucasia. Hostilities were initiated in 627 AD by Khagan Tong Yabghu of the Western Göktürks and Emperor Heraclius of the Eastern Roman Empire. Opposing them were the Sassanid Persians, allied with the Pannonian Avars.