Zipoetes I of Bithynia: Founder of Dynastic Kingship in the Hellenistic Era

Introduction

Zipoetes I (also rendered Zipoites or Ziboetes; c. 354–278 BC) was the ruler of Bithynia from about 326 BC until his death. He succeeded his father Bas and is credited with establishing dynastic kingship in Bithynia; most accounts record a forty–eight year reign. During his rule he fought protracted wars against Hellenistic neighbors, notably Lysimachus and Antiochus, son of Seleucus I Nicator.

His expansionist policy brought him into conflict with Greek cities on the Propontis. In 315 BC he attacked Astacus and Chalcedon but was repulsed by a relief force sent by Antigonus I Monophthalmus; after Antigonus’ death Zipoetes renewed operations in 301 BC and prevailed, though Astacus was destroyed in the fighting. He founded a city called Zipoetium at the foot of Mount Lypedron; the exact locations of both are not preserved in the sources.

In 297 BC Zipoetes became the first Bithynian ruler to assume the title basileus, and his successors treated that year as the epochal first year of the Bithynian calendar, a dating system used in some places as late as the fifth century AD. He died around 278 BC, leaving four sons; the eldest, Nicomedes, succeeded him. His principal legacy is the establishment of a royal title and a dynastic chronology that shaped Bithynian identity in the Hellenistic period and beyond.