About Vonones II, King of Parthia
http://www.rpi.edu/~holmes/Hobbies/Genealogy/wc20/wc20_316.htm -------------------- Vonones II of Parthia ruled the Parthian Empire briefly in 51. During the reign of his brother Gotarzes II he was governor of Media, and was raised to the throne on Gotarzes' death. However, he died after a few months and was succeeded by his son Vologases I. --------------------
From Wikipedia, the free encyclopedia
Parthian Empire at its greatest extent, c. 60 BCE.
Capitals Ctesiphon, Hecatompylus
Area Middle East
Existed 238 BCE–228 CE
Parthia was a civilization situated in the northeast of modern Iran, but at its height covering all of Iran proper, as well as regions of the modern countries of Armenia, Iraq, Georgia, eastern Turkey, eastern Syria, Turkmenistan, Afghanistan, Tajikistan, Pakistan, Kuwait, the Persian Gulf coast of Saudi Arabia, Bahrain, Qatar, and UAE.
Parthia was led by the Arsacid dynasty, who reunited and ruled over the Iranian plateau, taking over the eastern provinces of the Greek Seleucid Empire, beginning in the late 3rd century BC, and intermittently controlled Mesopotamia between ca 150 BC and 224 AD. It was the third native dynasty of ancient Iran (after the Median and the Achaemenid dynasties). Parthia (mostly due to their invention of heavy cavalry) was the arch-enemy of the Roman Empire in the east; and it limited Rome's expansion beyond Cappadocia (central Anatolia).
After the Scythian-Parni nomads (Assyrians called them Ashkuz) had settled in Parthia and had built a small independent kingdom, they rose to power under king Mithridates the Great (171–138 BC). Later, at the height of their power, Parthian influence reached as far as Ubar in Arabia, the nexus of the frankincense trade route, where Parthian-inspired ceramics have been found. The power of the early Parthian empire seems to have been overestimated by some ancient historians, who could not clearly separate the powerful later empire from its more humble obscure origins. The end of this long-lived empire came in 224 AD, when the empire was loosely organized and the last king was defeated by one of the empire's vassals, the Persians of the Sassanid dynasty.
Little is known of the Parthians; not much of their own literature has survived. Consequently Parthian history is largely derived from foreign histories, controlled by the evidence of coins and inscriptions; even their own name for themselves is debatable due to a lack of domestic records. Several Greek authors, of whom we have fragments, including Apollodorus of Artemita and Isidore of Charax, wrote under Parthian rule. Their power was based on a combination of the guerilla warfare of a mounted nomadic tribe, with organisational skills sufficient to build and administer a vast empire - even though it never matched in power the Persian empires that preceded and followed it. Vassal kingdoms seem to have made up a large part of their territory (see Tigranes II of Armenia), and Hellenistic cities enjoyed a certain autonomy; their craftsmen received employment by some Parthians.
Strabo considered Parthians to be Carduchi, i.e., the inhabitants of Curdistan.
1 Parthia as a satrapy
2 The Parthian Empire
4 Parthian language
5 Contact with China
6 Conflicts with Rome
7 Expansion to India
8 Decline and fall
9 Parthian rulers
Parthia as a satrapy
Parthia originally designated a territory southeast of the Caspian sea. It was a satrapy of the Achaemenid Empire, which was conquered by Alexander the Great circa 330 BCE. Following Alexander's death, the government of Parthia was given to Nicanor, at the Partition of Babylon in 323 BCE. At the Partition of Triparadisus in 320 BCE, Parthia was given to Philip. Philip was then succeeded by Peithon. From 311 BCE Parthia then became a part of the Seleucid empire, being ruled by various satraps under a Seleucid king.
Andragoras (?-238 BCE) was the last Seleucid satrap of the province of "Partahia", under the Seleucid rulers Antiochus I Soter and Antiochus II Theos (Justin, xli. 4). Andragoras tried to wrestle independence from the Seleucid Empire, at a time when the Seleucid were embroiled in conflict with Ptolemaic Egypt. In defiance, he issued coins in which he wears the royal diadem as well as his name (Will: I, 1966). Andragoras was a neighbour, a contemporary, and probably an ally of Diodotus I in Bactria, who also wrestled independence around the same time, giving rise to the Greco-Bactrian kingdom.
The Parthian Empire
The tribe of the Parni, a nomadic people of Iranian origin, who originally spoke an Eastern Iranian language and later known as the Parthians, entered the Iranian plateau from Central Asia. They were consummate horsemen, known for the 'Parthian shot': turning backwards at full gallop to loose an arrow directly to the rear. Initially, ca. 238 BCE, their king named Arsaces (Ashk) toppled Andragoras and established his dynasty's independence from Seleucid rule in remote areas of northern Iran in what is today known as Turkmenistan.
"He (Arsaces) was used to a life of pillage and theft, when he heard about the defeat of Seleucus against the Gauls. Relieved from his fear of the king, he attacked the Parthians with a band of thieves, vanquished their prefect Andragoras, and, after having killed him took the power over the nation" Justin, xli. 4.
The descendants of Arsaces ruled until Antiochus III the Great invaded Parthia in 209 BC, occupied the capital Hecatompylus and pushed forward into Hyrcania. The Parthian king Arsaces II apparently successfully sued for peace, and Parthia recognized Seleucid authority. Antiochus III had so well secured Parthia that he moved further east into Bactria, where he fought the Greco-Bactrian king Euthydemus I for three years, and then went into India.
It was not until the 2nd century BC that the Parthians were able to profit from the continuing erosion of the Seleucid Empire, gradually capturing all its territories east of Syria. Once the Parthians had gained Herat, the movement of trade along the Silk Road to China was effectively choked off and the post-Alexandrian Hellenistic Greco-Bactrian Kingdom was doomed.
The Seleucid monarchs attempted to "hold the line" against the Parthian expansion; Antiochus IV Epiphanes spent his last years on a campaign against the newly emerging Iranian states. After his death in 164 BC, the Parthians took advantage of the ensuing dynastic squabbles to make even greater gains.
.In 139 BC, the Parthian king Mithridates I captured the Seleucid monarch Demetrius II Nicator, holding him captive for ten years while his troops overwhelmed Mesopotamia and Media.
By 129 BC the Parthians were in control of all the lands right to the Tigris, and established their winter encampment on its banks at Ctesiphon, downstream from modern Baghdad. Ctesiphon was then a small suburb directly across the river from Seleucia on the Tigris, the most Hellenistic city of western Asia. Because of their need of the wealth and trade provided by Seleucia, the Parthian armies limited their incursions to harassment, allowing the city to preserve its independence. In the heat of the Mesopotamian summer, the Parthian army would withdraw to the ancient Persian capitals of Susa and Ecbatana (modern Hamadan).
From around 130 BCE, the Parthians suffered numerous incursions by Scythian nomads (also called the Tocharians from Bactria, possibly the Yuezhi), in which kings Phraates II and Artabanus I were successively killed. Scythians again invaded Parthia around 90 BCE, putting king Sanatruces on the Parthian throne.
After the conquest of Media, Assyria, Babylonia and Elam, the Parthians had to organize their empire. The former elites of these countries were Greek, and the new rulers had to adapt to their customs if they wanted their rule to last. As a result, the cities retained their ancient rights and civil administrations remained more or less undisturbed. An interesting detail is coinage: legends were written in the Greek alphabet, a practice that continued until the 2nd century AD, when local knowledge of the language was in decline and few people knew how to read or write the Greek alphabet.
Another source of inspiration was the Achaemenid dynasty that had once ruled the Persian Empire. Courtiers spoke Persian and used the Pahlavi script; the royal court traveled from capital to capital, and the Arsacid kings styled themselves "king of kings". It was an apt title, as in addition to his own kingdom the Parthian monarch was the overlord of some eighteen vassal kings, such as the rulers of the city state Hatra, the kingdom of Characene and the ancient kingdom of Armenia.
The empire was, overall, not very centralized. There were several languages, many peoples, and a number of different economic systems. The loose ties between the separate parts of the empire were a key to its survival. In the 2nd century AD, the most important capital, Ctesiphon, was captured no less than three times by the Romans (in 116, 165 and 198 AD), but the empire survived because there were other centers of power. On the other hand, the fact that the empire was a mere conglomeratation of kingdoms, provinces and city-states did at times seriously weaken the Parthian state. This was a major factor in the halt of the Parthian expansion after the conquests of Mesopotamia and Persia.
Local potentates played important roles, and the king had to respect their privileges. Several noble families had votes in the Royal council; the Suren-Pahlav Clan had the right to crown the Parthian king, and every aristocrat was allowed and expected to retain an army of his own. When the throne was occupied by a weak ruler, divisions among the nobility became dangerous.
The constituent parts of the empire were surprisingly independent. For example, they were allowed to strike their own coins, a privilege which in antiquity was very rare. As long as the local elite paid tribute to the Parthian king, there was little interference. The system worked well: towns like Ctesiphon, Seleucia, Ecbatana, Rhagae, Hecatompylos, Nisâ, and Susa flourished.
Tribute was one source of royal income; another was tolls. Parthia controlled the Silk Road, the trade route between the Mediterranean Sea and China.
Parthian is a now-extinct ancient Northwestern Iranian language that originated in Parthia (a region in north-east of modern Iran and the Greater Khorasan, including southern part of what is today known as Turkmenistan) and was the official language of the Parthian Empire under the Arsacid Dynasty (248 BC - 224 AD).
Contact with China
The Chinese explorer Zhang Qian, who visited the neighbouring countries of Bactria and Sogdiana in 126 BC, made the first known Chinese report on Parthia. In his accounts Parthia is named "?nx?" (Chinese: ??), a transliteration of "Arsacid", the name of the Parthian dynasty. Zhang Qian clearly identifies Parthia as an advanced urban civilization, which he equates to those of Dayuan (in Ferghana) and Daxia (in Bactria).
"Anxi is situated several thousand li west of the region of the Great Yuezhi (in Transoxonia). The people are settled on the land, cultivating the fields and growing rice and wheat. They also make wine out of grapes. They have walled cities like the people of Dayuan (Ferghana), the region contains several hundred cities of various sizes. The coins of the country are made of silver and bear the face of the king. When the king dies, the currency is immediately changed and new coins issued with the face of his successor. The people keep records by writing on horizontal strips of leather. To the west lies Tiaozhi (Mesopotamia) and to the north Yancai and Lixuan (Hyrcania)." (Shiji, 123, Zhang Qian quote, trans. Burton Watson).
Following Zhang Qian's embassy and report, commercial relations between China, Central Asia, and Parthia flourished, as many Chinese missions were sent throughout the 1st century BC: "The largest of these embassies to foreign states numbered several hundred persons, while even the smaller parties included over 100 members... In the course of one year anywhere from five to six to over ten parties would be sent out." (Shiji, trans. Burton Watson).
The Parthians were apparently very intent on maintaining good relations with China and also sent their own embassies, starting around 110 BC: "When the Han envoy first visited the kingdom of Anxi (Parthia), the king of Anxi dispatched a party of 20,000 horsemen to meet them on the eastern border of the kingdom... When the Han envoys set out again to return to China, the king of Anxi dispatched envoys of his own to accompany them... The emperor was delighted at this." (Shiji, 123, trans. Burton Watson).
In 97 the Chinese general Ban Chao went as far west as the Caspian Sea with 70,000 men and established direct military contacts with the Parthian Empire.
Parthians also played a role in the Silk Road transmission of Buddhism from Central Asia to China. An Shih Kao, a Parthian nobleman and Buddhist missionary, went to the Chinese capital Luoyang in 148 where he established temples and became the first man to translate Buddhist scriptures into Chinese.
Conflicts with Rome
Main article: Roman relations with the Parthians and Sassanians
.In 53 BC, the Roman general Crassus invaded Parthia, but was defeated at the Battle of Carrhae by a Parthian commander called Surena in the Greek and Latin sources, most likely a member of the Suren-Pahlav Clan. This was the beginning of a series of wars that were to last for almost three centuries.
The Parthian armies included two types of cavalry: the heavily-armed and armoured cataphracts and lightly armed but highly-mobile mounted archers. For the Romans, who relied on heavy infantry, the Parthians were too hard to defeat, as both types of cavalry were much faster and more mobile than foot soldiers. On the other hand, the Parthians found it difficult to occupy conquered areas as they were unskilled in siege warfare. Because of these weaknesses, neither the Romans nor the Parthians were able to completely defeat each other.
In the years following the battle of Carrhae the Romans were divided in civil war between the adherents of Pompey and those of Julius Caesar and hence unable to campaign against Parthia. Although Caesar was eventually victorious against Pompey and was planning a campaign against Parthia, his subsequent murder led to another civil war. The Roman general Quintus Labienus, who had supported Caesar's murderers and feared reprisals from his heirs, Mark Antony and Octavian (later Augustus), sided with the Parthians and eventually became the best general of king Pacorus I. In 41 BC Parthia, led by Labienus, invaded Syria, Cilicia, and Caria and attacked Phrygia in Asia Minor. A second army intervened in Judaea and captured its king Hyrcanus II. The spoils were immense, and put to good use: King Phraates IV invested them in building up Ctesiphon.
In 39 BC, Antony retaliated, sending out the old warhorse general Publius Ventidius Bassus and several of Caesar's crack, veteran legions to secure the conquered territories. The Parthian King Pacorus was killed along with Labienus, and the Euphrates again became the border between the two nations. Hoping to further avenge the death of Crassus, Antony invaded Mesopotamia in 36 BC with the Legion VI Ferrata and other units. Having cavalry in support, Antony reached Armenia but ceased his advance as civil war again broke out in Rome.
Antony's campaign was followed by a break in the fighting between the two empires as Rome was again embroiled in civil war. When Octavian defeated Mark Antony, he ignored the Parthians, being more interested in the west. His son-in-law and future successor Tiberius negotiated a peace treaty with Phraates (20 BC).
At the same time, around the year 1, the Parthians became interested in the valley of the Indus, where they began conquering the petty kingdoms of Gandhara. One of the Parthian leaders was Gondophares, king of Taxila; according to an old and widespread Christian tradition, he was baptized by the apostle Thomas. While it may sound far-fetched, the story is not altogether impossible: adherents of several religions lived together in Gandara and the Punjab, and there may have been an audience for a representative of a new Jewish sect.
War broke out again between Rome and Parthia in the 60s. Armenia had become a Roman vassal kingdom, but the Parthian king Vologases I appointed a new Armenian ruler. This was too much for the Romans, and their commander Gnaeus Domitius Corbulo invaded Armenia. The result was that the Armenian king received his crown again in Rome from the emperor Nero. A compromise was worked out between the two empires: in the future, the king of Armenia was to be a Parthian prince, but his appointment required approval from the Romans.
Expansion to India
Main article: Indo-Parthian Kingdom
Also during the 1st century BC, the Parthians started to make inroads into eastern territories that had been occupied by the Indo-Scythians and the Yuezhi. The Parthians gained control of parts of Bactria and extensive South Asian territories in modern day Pakistan, after defeating local rulers such as the Kushan Empire ruler Kujula Kadphises, in the Gandhara region.
The ruins of the ancient port city of Siraf are in the process of excavation, and its historical importance to ancient trade is only now being realized. Discovered there in archaeological excavations are ivory objects from east Africa, pieces of stone from India, and lapis from Afghanistan. Sirif dates back to the Parthian era.
Around 20 AD, Gondophares, one of the Parthian conquerors, declared his independence from the Parthian empire and established the Indo-Parthian Kingdom in the conquered territories.
Decline and fall
The Armenian compromise served its purpose, but nothing in it covered the deposition of an Armenian king. After 110 AD, the Parthian king Vologases III dethroned the Armenian ruler, and the Roman emperor Trajan decided to invade Parthia in retaliation. War broke out in 114 AD and the Parthians were severely beaten. The Romans conquered Armenia, and in the following year, Trajan marched to the south, where the Parthians were forced to evacuate their strongholds. In 116 AD, Trajan captured Ctesiphon, and established new provinces in Assyria and Babylonia. Later that year he took the Parthian capital, Susa, deposed the Parthian King Osroes I and put Parthamaspates as a puppet ruler on the throne.
Rebellions soon broke out due to the continuing loyalty of the population to Parthia. At the same time, the diasporic Jews revolted and Trajan was forced to send an army to suppress them. Trajan overcame these troubles, but his successor Hadrian gave up the territories (117 AD).
Parthian weaknesses also contributed to the disaster. In the first century AD, the Parthian nobility had become more powerful due to concessions by the Parthian king granting them greater powers over the land and the peasantry. Their power now rivaled the king's, while at the same time internal divisions in the Arsacid family had rendered them vulnerable.
But the end was not near, yet. In 161 AD king Vologases IV declared war against the Romans and reconquered Armenia. The Roman counter-offensive was slow, but in 165 AD, Ctesiphon fell, and the Parthians were only saved by the outburst of a catastrophic epidemic (probably the measles) which temporarily crippled the two empires. The Roman emperors Lucius Verus and Marcus Aurelius added northern Mesopotamia to their realm (partly as a vassal-kingdom), but as it was never secure enough for them to demilitarize the region between the Euphrates and Tigris. It remained an expensive burden.
The deciding blow came thirty years later. King Vologases V had tried to reconquer Mesopotamia during another Roman civil war (193 AD), but was repulsed when general Septimius Severus counter-attacked. Again, Ctesiphon was captured (198 AD), and large spoils were brought to Rome. According to a modern estimate, the gold and silver were sufficient to postpone a European economic crisis for three or four decades, and the consequences of the looting for Parthia were dire.
Parthia, now impoverished and without any hope to recover the lost territories, was demoralized. The kings were forced to concede greater powers to the nobility, and the vassal kings began to waver in their allegiance. In 224 AD, the Persian vassal king Ardašir revolted. Two years later, he took Ctesiphon, and this time it meant the end of Parthia, replaced by a third Persian Empire, ruled by the Sassanid dynasty.
Arsaces I c. 247–211 BC (In some histories, Arsaces's brother Tiridates I is said to have ruled c. 246–211 BC.)
Arsaces II c. 211–191 BC (frequently called Artabanus by early scholars)
Phriapatius c. 191–176 BC
Phraates I c. 176–171 BC
Mithridates I c. 171–138 BC
Phraates II c. 138–127 BC
Artabanus I c. 127–124 BC
Mithridates II c. 123–88 BC
Gotarzes I c. 95–90 BC
Orodes I c. 90–80 BC
Unknown king, c. 80–77 BC
Sanatruces c. 77–70 BC
Phraates III c. 70–57 BC
Mithridates III c. 57–54 BC
Orodes II c. 57–38 BC
Pacorus I c. 39–38 BC (co-ruler with his father Orodes II)
Phraates IV c. 38–2 BC
Tiridates II c. 30–26 BC
Phraates V (Phraataces) c. 2 BC–AD 4
Musa c. 2 BC–AD 4 (co-ruler with her son Phraates V)
Orodes III c. AD 6
Vonones I c. 8–12
Artabanus II c. 10–38
Tiridates III c. 35–36
Vardanes I c. 40–47
Gotarzes II c. 40–51
Sanabares c. 50–65
Vonones II 51
Vologases I c. 51–78
Vardanes II c. 55–58
Vologases II c. 77–80
Pacorus II c. 78–105
Artabanus III c. 80–90
Vologases III c. 105–147
Osroes I c. 109–129
Parthamaspates c. 116
Mithridates IV c. 129–140
Unknown king c. 140
Vologases IV c. 147–191
Osroes II c. 190 (rival claimant)
Vologases V c. 191–208
Vologases VI c. 208–228
Artabanus IV c. 216–224
Hill, John E. 2004. The Western Regions according to the Hou Hanshu. Draft annotated English translation.
Hill, John E. 2004. The Peoples of the West from the Weilue ?? by Yu Huan ??: A Third Century Chinese Account Composed between 239 and 265 CE. Draft annotated English translation. 
^ Parthia derives from Latin Parthia, from Old Persian Parthava-, a dialectical variant of the stem Parsa-, from which Persia derives. Ashkanian appears to have come from the Sassanian chronicles, from which they entered in Ferdowsi's epic poem Shahnama.
^ History of the Decline and Fall of the Roman Empire, Chapter 21.
^ Foreign Experts Talk of Siraf History. Cultural Heritage News Agency. Retrieved on 2006-12-11.
Overview of Parthian History
There was a district named Partukka or Partakka which was known to the Assyrians as early as the seventh century B.C., and it may have formed a part of Media. Media was conquered by Cyrus (Kurush) the Great, founder of the Achaemenid empire.
The Achaemenids ruled Iran from 550 B.C. to 330 B.C. and their authority extended from the Danube river to the Indus river at its zenith. Under the Achaemenids, there was a satrapy named Parthava, probably gained by conquest between 546 and 539 B.C. during Cyrus the Great's campaign south and east of the Caspian Sea. (Debevoise, Political History, 4) At that time the satrapy included Hyrcania, which lay between the Elburz mountains and the Caspian Sea. Parthava revolted in 521 B.C., but was subdued and probably remained united with Hyrcania at the death of Darius. Later it was apparently separated from Hyrcania and then joined with Chorasmia. In the army of Xerxes, there was a contingent of Parthians under the command of a certain Artabazus son of Pharnaces, probably the satrap of Parthia. Among the Parthians killed in Xerxes' Greek campaign was a cavalry leader named Arsaces. (Aeschylus, Persae, 4) The last ruler of the Achaemenid line was Darius III Condomannus who was defeated by Alexander the Great. The Parthians fought on the side of the Achaemenids against Alexander at Arbela and Darius' satrap of Parthia, Phrataphernes, surrendered to Alexander in Hyrcania. (Arrian, Anabasis, iii)
After defeat by Alexander, Amminapses, a Parthian from Egypt, was made Alexander's satrap of Parthia, which had been joined with Hyrcania. In 318 B.C. Pithon, satrap of Media, seized Parthia and installed his brother Eudamus. But other satraps became alarmed and united under Peucestas of Persis to drive Pithon back to Media. (Justin xiii, 4. 23) After 316 B.C. the province was apparently joined to Bactria under the command of Stasanor. But after nearly a century of Macedonian Greek rule by Alexander and his Seleucid successors, the nearly continuous war with Egypt weakened the Seleucids to the point that Diodotus of Bactria revolted and declared himself king circa 253 B.C. (Justin xli, 4. 5)
The origins of the Parthian people are clouded. Strabo (xi, 515) says the first Arsaces was a Scythian man with the semi-nomadic Parni tribe, a part of the Dahi, nomads who lived along the Ochus (Tejend or lower Oxus) River, who invaded and conquered Parthia. Strabo also mentions those who claim Arsaces was a Bactrian who escaped from Diodotus after a failed revolt. Justin (xli, 1) agrees Arsaces was a Scythian. Frye's analysis is that we can believe the Parni origins, but it was more likely a migration than an invasion that brought them, and Arsaces, to Parthia. (History, p. 207) These people would not be known as Parthians until they moved southward into the Persian province of Parthava sometime before 250 B.C. Achaemenian and early Greek references to "Parthians" refer to earlier inhabitants of Parthava, not the Arsacid Parthians. (Debevoise, Political History, 2; W. M. Montgomery, Early Empires).
The Parthians took encouragement from Diodotus' success and in 247 B.C. rose against Andragoras, satrap of Parthia for Antichus II Theos (261-247 B.C.). This date is fixed by a double-dated tablet discovered by George Smith (Assyrian Discoveries, London, 1875). The revolt was led by the brothers Arsaces and Tiridates. Arsaces became king and his name the honorific used by all subsequent Parthian kings.
During the second century B.C., the Parthians were able to extend their rule to Bactria, Babylonia, Susiana, and Media, and under Mithradates II (c. 123 - 88 B.C.), Parthian conquests stretched from Armenia to India. After the victories of Mithradates II, the Parthians began to claim descent from both the Greeks and the Achaemenids. They spoke a language similar to that of the Achaemenids, used the Pahlavi script, and established an administrative system based on Achaemenid precedents.
Parthian "Dark Age" c. 95 - 57 B.C.
The most confused period of Parthian history is from the late years in the reign of Mithradates II (ended c. 88 B.C.) to the establishment of the sole rule of Orodes II c. 57 B.C. While Mithradates II was still in power, we have coins from Gotarzes I (c. 95 - 90 B.C.), Orodes I (c. 90 - 80 B.C.). And during the period immediately following the reign of Mithradates II, we see overlapping coinages of Orodes I (c. 90 - 80 B.C.), an Unknown King (I) c. 80 B.C., another Unknown King (II) (c. 80 - 70 B.C.), Sinatruces (c. 77 - 70 B.C.), and Darius of Media Atropatene (c. 70 B.C.). Phraates III appears to have consolidated control in the years around and following 70 B.C., and Orodes II took firm control c. 57 B.C. See the expanded discussion of this very confused period at the page on The Dark Age in Parthian History.
In 53 B.C. Crassus and over 40,000 Roman troops were annihilated by the Parthian forces of Orodes II and the peoples from the Mediterranean to the Indus understood the strength of Parthia. But by 40 B.C. even Rome had to acknowledge a Parthia whose forces, under the joint command of Pacorus I and Q. Labienus, a Roman, had struck directly into the heart of the Roman East and captured the provinces of Asia, Pamphylia, Cilicia, and Syria; even as far south as Petra, Parthia's word was law. For two years this vast area, so vital to Roman interests, was under Parthian occupation. Possession of the Carian and perhaps the Ionian coast by foreigners struck close to home as many Romans were native to that part of the world or did business there. The occupiers were no sooner pushed out by Ventidius than another Roman army under Anthony was defeated and barely escaped annihilation at Parthian hands. [Debevoise, 208]
The tug of war with Rome on the western border of Parthia continued almost without cease while Parthia had to constantly see to other threats from the north and east. The western border between Rome's dominions and Parthia gradually stabilized on the banks of the Euphrates, but war was always a threat and though major campaigns by the Romans were seen in A.D. 116, 161, 195, 217 and 232, Parthia was never conquered.
The Parthian landed nobility gained power and influence due to their their military power and increasing rights over the land and its peasants. As these grew, they were sufficient to allow the nobles to resist then defy the king, refusing to pay levies and failing to answer the call to arms that had been Parthia's source of power. Concurrently, the royal Arsacids fell to internal disagreements over succession which often ended in murder and a continued slide in their power. The resulting disorganization and fragmentation of the empire made way for successful Roman incursions into Parthian territories where rich commercial centers and royal treasuries were plundered, and territories lost to invaders. Petty kings rose to fill the power void; this power redistribution culminated in a direct attempts to overthrow the monarchy.
End of Empire
In A.D. 224, Ardashir, Parthian governor in the Achaemenid home province of Persis (Fars), overthrew Artabanus IV and established the Sasanid dynasty. The last Parthian king, Vologases VI, issued his last dated coin in A.D. 228. The Sasanians would rule Iran until the Islamic conquest in A.D. 641. The Sasanians were ardent Zoroastrians in conflict with their Armenian subjects who originally were Zoroastrians but subsequently embraced Christianity. The years of Sasanid rule saw a continuation of the struggle between Persia and Rome begun in the Parthian period. References to Parthia by Romans after A.D. 228 are to the Sasanid empire.
Strabo in Book 11 of his geography gives us one of the earliest accounts of the region and mentions the kingdom of Atropatene.
“ And then on the north by the Ocean as far as the mouth of the Caspian Sea; and then on the east by this same sea as far as the boundary between Albania and Armenia, where empty the rivers Cyrus and Araxes, the Araxes flowing through Armenia and the Cyrus through Iberia and Albania; and lastly, on the south by the tract of country which extends from the outlet of the Cyrus River to Colchis, which is about three thousand stadia from sea to sea, across the territory of the Albanians and the Iberians, and therefore is described as an isthmus.
... The other part is Atropatian Media, which got its name from the commander Atropates, who prevented also this country, which was a part of Greater Media, from becoming subject to the Macedonians. Furthermore, after he was proclaimed king, he organized this country into a separate state by itself, and his succession of descendants is preserved to this day, and his successors have contracted marriages with the kings of the Armenians and Syrians and, in later times, with the kings of the Parthians. ... Their royal summer palace is situated in a plain at Gazaca, and their winter palace in a fortress called Vera, which was besieged by Antony on his expedition against the Parthians. This fortress is distant from the Araxes, which forms the boundary between Armenia and Atropene, two thousand four hundred stadia, according to Dellius, the friend of Antony, who wrote an account of Antony's expedition against the Parthians, on which he accompanied Antony and was himself a commander.
Vonones II, King of Parthia's Timeline
Abt 27, Armenia
King of Armenia 52 AD Founder of Parthian Dynasty