strategic importance because it commanded the military routes between Asia
Minor and the heart of the Parthian country. To establish a protectorate
over Armenia was therefore the ambition of both Rome and Parthia. During
the presence of Augustus in the East (22-19 B. C.), Tiberius placed a
Roman nominee on the Armenian throne, and received from the Parthian king,
Phraates IV, the Roman standards and captives in Parthian hands, a success
which earned Augustus the salutation of _imperator_ from his troops. Later
Phraates sent four of his sons as hostages to Rome. But the Roman
protectorate over Armenia was by no means permanent; its supporters had
soon to give way to the Parthian party. Gaius Caesar between 1 B. C. and 2
A. D. restored Roman influence, but again the Parthians got the upper hand
and held it until 9 A. D., when Phraates was overthrown and was succeeded
by one of his sons whom Augustus sent from Rome at the request of the
Parthians.

*Judaea and Arabia.* To the south of the Roman province of Syria lay the
kingdom of Judaea, ruled by Herod until his death in 4 B. C., when it was
divided among his sons. Subsequently Judaea proper was made a province
administered by a Roman procurator. To the east of the Dead Sea was the
kingdom of the Nabataean Arabs, who controlled the caravan routes of the
Arabian peninsula and who were firm Roman allies. With their aid a Roman
army under Aelius Gallus in 25 B. C. sought to penetrate into the rich
spice land of Arabia Felix, but suffered such losses in its march across
the desert that it was forced to return without effecting a conquest. At
the same time Gaius Petronius defeated the Ethiopians under Queen Candace
and secured the southern frontier of Egypt. Through the ports of Egypt on
the Red Sea a brisk trade developed with India, from which distant land
embassies on various occasions came to Augustus. Further west in Africa,
Augustus added the kingdom of Numidia to the province of Africa, and
transferred its ruler, Juba II, whose wife was Cleopatra, daughter of
Antony the triumvir, to the kingdom of Mauretania (25 B. C.).

The conquests of Augustus established in their essential features the
future boundaries of the Roman Empire. At his death he left it as a maxim
of state for his successor to abstain from further expansion.

VI. THE ADMINISTRATION OF ROME

*The problem of police.* One of the great problems which had confronted
the Roman go