The Parthian [Arsacids] Empire encompassed the northeast region of present day Iran. It is the second significant era in the extensive history of Iran. After the collapse of the Achamenid Empire, the first significant era in the Iranian history, the Greeks had taken over the governing of the land. In 247 BCE, Arsaces, a Parni leader, revolted against the Greek ruling and the Seleucid Empire advanced in the east. He had now established the Parthian Empire. Tiridates then succeeded his brother Arsaces. He consolidated the Parthian power in the east. In 211 BCE, Tiridates was succeeded by Artabanus I. He increased Parthian domains, including the Iranian Plateau and Tigris/Euphrates River Valley. 171-139 BCE, Mithridates I ruled. He took back the remainder of Iran from the Greeks and issued the first Parthian coins that were based on Greek models. In 124-88 BCE, Mithridates II ruled. He recovered all previously lost territories from the loss due to the fall of the Acheaemind Empire. He also expanded the empire, westward into present day Armenia and Syria, northward as far as Merv, and eastward keeping the Sakas under control. The first sign of trouble came in 96 BCE, under Mithridates II, when Parthia confronts Rome. In 92 BCE, Mithridates II was able to conclude the first treaty between Parthia and Rome. Euphrates was established as a mutual boundary. Upon the death of Mithridates II, external relations remained tense, and rival dynastic claimants fight for major territories became more prominent. The Emperor Orodes II gained succession after Mithridates II. During his reign, problems between the Roman and Parthian Empires had reached the point of war. Rome had initiated the wars, wanting to take the inheritance of Alexander the Great of the Greeks, believing it was their own. In 54 BCE, The Roman general Crassus claimed he could conquer Parthian Mesopotamia, but in 53 BCE, the Parthians defeated the Romans and Crassus was killed, by beheading. In 36 BCE, Phraates IV, son of Orodes II, gained control of the empire. He had defeated the Roman forces, that were in Armenia and media Atropatene under Mark Antony's rule, during his reign. The Romans could not claim anything beyond the Euphrates River. In 65 CE, the Roman Emperor crowned Tiridates king of Persia to demonstrate the balance of power. Vologases I, the brother of Tiridates, took control through 51-76 CE. This time was noted for consolidation. The decline of the Parthian Empire was due to the Romans invading and sacking the Parthian Empire. In the east, the rise of the Kushan Dynasty came, and the west, the province of Persia in the Parthian Empire gained more power. The Emperor Vologases dealt with the new Roman campaigns against the Parthians and the usurpation of his brother who became the Emperor Artabanus V. The Empire was further weakened by the invasions of border people and the Romans. In 222 CE, Ardashir, the ruler of Persia, successfully revolted against Artabanus V. This ended the Parthian rule over Persia and began the ruling of the Sassanids.

Parthian Kings:
Arsaces I (250 - 247 BCE)
Tiridates (247 - 211 BCE)
Artabanus I (211 - 191 BCE)
Phriapathus (191 - 176 BCE)
Phraates I (176 - 171 BCE)
Mithradates I (171 - 139 BCE)
Phraates II (139 - 129 BCE)
Interregnum (128 BCE)
Artabanus II (128 - 124 BCE)
Mithradates II, The Great (124 - 88 BCE)
Gotarzes I [rebel king] (95 - 90 BCE)
Orodes I (90 - 80 BCE)
Sinatruces (80 - 70 BCE)
Phraates III (70 - 57 BCE)
Mithradates III (57 - 54 BCE)
Orodes II (54 - 38 BCE)
Pacorus I [co-ruler] (41 - 38 BCE)
Phraates IV (38 - 29 BCE)
Tiradates I [rebel king] (29 - 27 BCE)
Phraataces (2 BCE - 4 CE)
Orodes III (6 CE)
Vonones I (8 - 12 CE)
Artabanus III (10 - 38 CE)
Tiridates II [rebel king] (35 - 36 CE)
Vardanes I (40 - 47 CE)
Gotarzes II (40 - 51 CE)
Sanabares [rebel king] (50 - 56 CE)
Vonones II (51 CE)
Vologases I (51 - 78 CE)
Vardanes II [rebel king] (55 - 58 CE)
Vologases II (78 - 80 CE)
Pacorus II (80 - 105 CE)
Artabanus III [rebel king] (80 - 90 CE)
Vologases III (105 - 147 CE)
Osroes I [co-ruler] (109 - 129 CE)
Parthamaspates [rebel king, supported by the Romans] (116 CE)
Mithradates IV (140 CE)
Vologases IV (147 - 191 CE)
Osroes II [rebel king] (190 CE)
Vologases V (191 - 208 CE)
Vologases VI (208 - 218 CE)
Artabanus V (216 - 224 CE)