Parthian Empire

   A large realm that overcame and replaced the Greek-run Seleucid Empire in the second century b.c., bringing Mesopotamia under Parthian rule for nearly four centuries. The Parthians were originally a nomadic people from central Asia who spoke an Indo-European tongue and excelled at horse breeding and horsemanship. Sometime in the mid-first millennium b.c., bands of Parthians began migrating into northern Iran, then part of the Achaemenid Persian Empire. This region became known as Parthava. After the fall of Persia to the Greeks and the incorporation of much of its territory into the Seleucid Empire, more Parthian tribes entered Parthava, now a Seleucid province. But the people of the region became increasingly discontent with Seleucid rule. In 247 b.c. a local Parthian leader, Arsaces, declared himself king of the local Parthian tribes, marking the start of the Arsacid dynasty, named for him. Arsaces defeated the Seleucid governor of Parthava in battle in 238 b.c., thereby taking firm hold of northern Iran and launching the Parthian realm.

   In the decades that followed, the Parthians steadily chipped away at the Seleucid state. They captured the Silk Road, an important trade route stretching eastward to India and China, thereby robbing the Seleucids of valuable revenues. Then, in 141 b.c., the Parthian ruler Mith-ridates I (reigned 171-ca. 138 b.c.) annexed Mesopotamia, including its two leading cities, Babylon and Seleucia. The Parthians proceeded to build a new capital, Ctesi-phon, on the Tigris River not far from Seleucia. Highly tolerant of the beliefs and customs of other peoples, they allowed the Greek and Mesopotamian residents of seleucia and other cities in the region to preserve their cultures. in fact, the Parthians admired Greek culture and appointed numerous Greeks to important administrative posts. The result was the rise of a sort of Greco-iranian culture in the region that over time reduced the importance of Persian traditions, including the old Persian Zoroastrian religion.

   Though the Parthians had managed to gain control of large sectors of the Near East, they lacked the strong central organization needed to hold together such a large, diverse realm indefinitely. There was no overall, national army, for instance. instead, small local armies commanded by individual chiefs (the heads of noble families) came together when necessary and supported the "head chief," the king. Thus, the Parthian Empire was in some ways a feudal state in which a number of vassal lords swore allegiance to the strongest of their number.

   This loose political structure was viewed as weak by the Romans, who set out to incorporate the Parthian lands into their own empire. The Roman general Marcus Crassus invaded Mesopotamia in 53 b.c. but was defeated and killed at Car-rhae (Harran). Later Roman forays into the region were more successful, however. In a.d. 116 the emperor Trajan (reigned 98-117) destroyed Ctesiphon and conquered large portions of Mesopotamia. Trajan's successor, Hadrian (117-138), gave up the captured territories, thinking them too difficult to rule from faraway Italy. But the emperor Marcus Aurelius (161-180) reversed this policy and seized northern Mesopotamia. Not long afterward, one of his own successors, Septimius Severus (193-211), recaptured Ctesiphon and looted much of the countryside.

   The Parthians were unable to recover from this series of devastating onslaughts, and dissention steadily formed among the surviving Parthian vassal rulers. In 224 one of them, Ardashir, who ruled in the old Persian heartland of Fars, defeated the last Parthian king, Artabanus IV (reigned 216224) and established a new Persian realm, the Sassanian Empire.

   See also: Ardashir I; Ctesiphon; Romans; Sassanian Empire