of his pioneer induced Abu-bekr to support the war
in this quarter with vigor. Reinforcements joined Kaled from every side,
and in a short time he found himself at the head of an army of 18,000
men. With this force he proceeded southwards bent on reducing the entire
tract between the desert and the Eastern or real Euphrates. The most
important city of the southern region was at the time Obolla which was
situated on a canal or backwater derived from the Euphrates, not far
from the modern Busrah. It was the great emporium for the Indian trade,
and was known as the _limes Indorum_ or "frontier city towards India."
The Persian governor was a certain Hormuz or Hormisdas who held the
post with 20,000 men. Kaled fought his second great battle with this
antagonist, and was once more completely victorious, killing Hormuz,
according to the Arabian accounts, with his own hands. Obolla
surrendered; a vast booty was taken; and, after liberally rewarding
his soldiers Kaled sent the fifth part of the spoils, together with a
captured elephant, to Abu-bekr at Medina. The strange animal astonished
the simple natives, who asked one another wonderingly "Is this indeed
one of God's works, or did human art make it."

The victories of Kaled Over Asadsubeh and Hormuz were followed by a
number of other successes, the entire result being that the whole of
the fertile region on the right bank of the Euphrates from Hit to the
Persian Gulf, was for the time reduced, made a portion of Ahu-bekr's
dominions, and parcelled out among Mohammedan governors. Persia was
deprived of the protection which a dependent Arab kingdom to the west of
the river had hitherto afforded her, and was brought into direct contact
with the great Mohammedan monarchy along almost the whole of her western
frontier. Henceforth she was open to attack on this side for a distance
of above four hundred miles, with no better barrier than a couple of
rivers interposed between her enemy and her capital.

Soon after his conquest of the kingdom of Hira, Kaled was recalled
from the Euphrates to the Syrian war, and was employed in the siege of
Damascus, while Persia enjoyed a breathing-space. Advantage was taken of
this interval to stir up disaffection in the newly-conquered province.
Rustam appointed to the command against the Arabs by Isdigerd sent
emissaries to the various towns of the Sawad, urging them to rise in
revolt and promising to support such a movement with a Persian army. The