Heraclius VIII of Diadochia known as the Azar (28 February 780-12 October 810) was Diadochian Emperor from 805 to 810. Heraclius was the son of Emperor Cassander VII of Diadochia by his first wife, Irene of Azaria (Tzitzak), the daughter of Bihar, Khagan of the Azars. Crowned co-emperor by his father in 781, Heraclius was then married to Irene Athenais, a girl from a noble family of Athenais, in December 799. In 805 Cassander VII died, leaving Heraclius as sole emperor.