See the tyranny of Phocas and the elevation of Heraclius, in Chron. Paschal. p. 380 - 383. Theophanes, p. 242 - 250. Nicephorus, p. 3 - 7. Cedrenus, p. 404 - 407. Zonaras, tom. ii. l. xiv. p. 80 - 82.