Ariobarzanes was the second king of Pontus

Pontus

Pontus or Pontos is a historical Greek designation for a region on the southern coast of the Black Sea, located in modern-day northeastern Turkey. The name was applied to the coastal region in antiquity by the Greeks who colonized the area, and derived from the Greek name of the Black Sea: Πόντος...

, succeeding his father Mithridates I Ctistes

Mithridates I of Pontus

Mithridates I Ctistes was the founder of the kingdom of Pontus in Anatolia....

 in 266 BC and died in an uncertain date between 258 and 240. He obtained possession of the city of Amastris

Amasra

Amasra is a small Black Sea port town in the Bartın Province, Turkey. The town is today much appreciated for its beaches and natural setting, which has made tourism the most important activity for its inhabitants...

 in Paphlagonia

Paphlagonia

Paphlagonia was an ancient area on the Black Sea coast of north central Anatolia, situated between Bithynia to the west and Pontus to the east, and separated from Phrygia by a prolongation to the east of the Bithynian Olympus...

, which was surrendered to him. Ariobarzanes and his father sought the assistance of the Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

s, who had come into Asia Minor

Anatolia

Anatolia is a geographic and historical term denoting the westernmost protrusion of Asia, comprising the majority of the Republic of Turkey...

 twelve years before the death of Mithridates, to expel the Egyptians

Ptolemaic Egypt

Ptolemaic Egypt began when Ptolemy I Soter invaded Egypt and declared himself Pharaoh of Egypt in 305 BC and ended with the death of queen Cleopatra VII of Egypt and the Roman conquest in 30 BC. The Ptolemaic Kingdom was a powerful Hellenistic state, extending from southern Syria in the east, to...

 sent by Ptolemy II Philadelphus

Ptolemy II Philadelphus

Ptolemy II Philadelphus was the king of Ptolemaic Egypt from 283 BCE to 246 BCE. He was the son of the founder of the Ptolemaic kingdom Ptolemy I Soter and Berenice, and was educated by Philitas of Cos...

. Ariobarzanes was succeeded by Mithridates II

Mithridates II of Pontus

Mithridates II , third king of Pontus and son of Ariobarzanes, whom he succeeded on the throne. He was a minor when his father died, but the period of his accession cannot be determined...

.