a military despotism, led to his
undoing, and in 602 he was murdered with his children. A like fate
befell the Emperor Phocas, who succumbed in 610 to the fortunes of
Heraclius, the son of Crispus, exarch of Africa. For thirty-two years
Heraclius ruled the Roman world. In three campaigns he chastised the
rising power of Persia, drove the armies of Chosroes from Syria,
Palestine, and Egypt, rescued Constantinople from the joint siege of the
Avars and Persians (626), and finally reduced the Persian monarch to the
defence of his hereditary kingdom. The deposition and murder of Chosroes
by his son Siroes (628) concluded the successes of the emperor.

A treaty of peace was arranged, and Heraclius returned in triumph to
Constantinople, where, after the exploits of six glorious campaigns, he
peacefully enjoyed the sabbath of his toils. The year after his return
he made the pilgrimage to Jerusalem to restore the true Cross to the
Holy Sepulchre. In the last eight years of his reign Heraclius lost to
the Arabs the same provinces which he had rescued from the Persians.

Heraclius died in 612. His descendants continued to fill the throne in
the persons of Constantine III. (641), Heracleonas (641), Constans II.
(641), Constantine IV. (668), Justinian II. (685), until 711, when an
interval of six years, divided into three reigns, made way for the rise
of the Isaurian dynasty.

_V.--The New Era of Charlemagne_

Leo III. ascended the throne on March 25, 718, and the purple descended
to his family, by the rights of heredity, for three generations. The
Isaurian dynasty is most notable for the part it played in
ecclesiastical history.

The introduction of images into the Christian Church had confused the
simplicity of religious worship. The education of Leo, his reason,
perhaps his intercourse with Jews and Arabs, had inspired him with a
hatred of images. By two edicts he proscribed the existence, as well as
the use, of religious pictures. This heresy of Leo and of his successors
and descendants, Constantine V. (741), Leo IV. (775), and Constantine
VI. (780), whose blinding by his mother Irene is one of the most tragic
stories of Roman history, justified the popes in rebelling against the
authority of the emperor, and in restoring and establishing the
supremacy of Rome.

Gregory II. saved the city from the attacks of the Lombards, who had
seized Ravenna and extinguished the series of Greek exarchs in 751. He
secured the assis