248 Death of Arsaces. His brother, =Tiridates=, succeeds, taking the name of Arsaces, which is also borne by all his successors as a throne name. They take the title of “king of kings.” 242 After defeat of Seleucus Callinicus at Ancyra, Tiridates invades Parthia, slays the eparch Andragores, and takes possession of the province. He next seizes Hyrcania, and causes a large army to oppose Seleucus. 238 Decisive victory of Tiridates over Seleucus. The latter is obliged to return to Antioch on account of civil war, and Tiridates is enabled to consolidate his kingdom. 211 Death of Tiridates. His son, =Arsaces II=, sometimes, but incorrectly, called =Artabanus=, succeeds. 209 Antiochus the Great wins a victory over Arsaces on the summit of Mount Labus. The Parthians retire to Sirynca and are besieged by Antiochus. Surrender of Sirynca, and treaty of peace. Arsaces retains Parthia, but is reduced to a vassal of Antiochus. Parthia remains undisturbed for some years. 191 =Phriapatius= or =Arsaces (III) Philadelphus= succeeds his father. Owing to the decay of Seleucid power, he acts as protector of the Greeks in his kingdom. 176 =Phraates I= or =Arsaces (IV) Theopator= succeeds his father. He conquers the Mardians. 171 Phraates dies, leaving the throne to his brother, =Mithridates I= or =Arsaces (V) Epiphanes=, who at once annexes several satrapies of Bactria to his kingdom. He holds court in Hyrcania. 155 At death of King Eucratides of Bactria, Mithridates continues the conquest of that country. The Hindu Kush becomes the eastern boundary of Parthia. Mithridates turns to the west. 147 The province of Babylonia is wrested from the Seleucids. The East is finally lost to the Macedonians. 139 Capture of Demetrius II of Syria, who has attempted to establish himself in Mesopotamia. 138 Successful campaign in Elymais. Death of Mithridates. He has made Parthia a great power. His son, =Phraates II= or =Arsaces (VI) Euergetes=, succeeds. He adds Margiana to the kingdom. The seat of the kingdom is transferred to Media. 130 Antiochus Sidetes begins a vigorous campaign against the Parthians, whom he defeats in a great battle on the Upper Zab. Babylon and Ecbatana are recovered. 129 The Parthians make secret terms with the Medes and attack Antiochus, whose host is annihilated and he himself slain. Phraates compelled to attack the Scythians, whom he had invited to assist him against Antiochus. They have arrived too late, and, as Phraates refuses to pay them, they begin to ravage the country.