eet on the Tigris, descended the stream to its mouth
and sailed into the Persian Gulf; he would have delighted, like
Alexander, in the conquest of India. He took from the Parthians the
country between the Euphrates and the Tigris--Assyria and
Mesopotamia--and erected there two Roman provinces.

To commemorate his conquests Trajan erected monuments which still
remain. The Column of Trajan on the Roman Forum is a shaft whose
bas-reliefs represent the war against the Dacians. The arch of triumph
of Benevento recalls the victories over the Parthians.

Of these two conquests one alone was permanent, that of Dacia. The
provinces conquered from the Parthians revolted after the departure of
the Roman army. The emperor Hadrian retained Dacia, but returned their
provinces to the Parthians, and the Roman empire again made the
Euphrates its eastern frontier. To escape further warfare with the
highlanders of Scotland, Hadrian built a wall in the north of England
(the Wall of Hadrian) extending across the whole island. There was no
need of other wars save against the revolting Jews; these people were
overthrown and expelled from Jerusalem, the name of which was changed
to obliterate the memory of the old Jewish kingdom.

Marcus Aurelius, the last of the Antonines, had to resist the invasion
of several barbarous peoples of Germany who had crossed the Danube on
the ice and had penetrated even to Aquileia, in the north of Italy. In
order to enroll a sufficient army he had to enlist slaves and
barbarians (172). The Germans retreated, but while Marcus was occupied
with a general uprising in Syria, they renewed their attacks on the
empire, and the emperor died on the banks of the Danube (180). This
was the end of conquest.

IMPERIAL ADMINISTRATION

=Extent of the Empire in the Second Century.=--The Roman emperors were
but little bent on conquest. But to occupy their army and to secure
frontiers which might be easily defended, they continued to conquer
barbarian peoples for more than a century. When the course of conquest
was finally arrested after Trajan, the empire extended over all the
south of Europe, all the north of Africa and the west of Asia; it was
limited only by natural frontiers--the ocean to the west; the
mountains of Scotland, the Rhine, the Danube, and the Caucasus to the
north; the deserts of the Euphrates and of Arabia to the east; the
cataracts of the Nile and the great desert to the south. The empire,
therefore, e