Ariarathes I (Ancient Greek: Ἀριαράθης, Ariaráthēs; ruled 331 BC or 330 BC – killed 322 BC), the son of the Cappadocian satrap Ariamnes I, was distinguished (Φιλάδελφος, Philádelphos) for his love of his brother Holophernes, whom he sent to assist his overlord king Artaxerxes III in the recovery of Egypt, 350 BC. Then he devotedly supported Darius III. Alexander the Great conquered Cappadocia during his route and installed a governor there (though two different names of this governor are given). Nevertheless, by the time of Alexander's death Ariarathes somehow assumed power as the first king of Cappadocians and even expanded the kingdom by subduing Cataonia. After the death of Alexander, 323 BC, Perdiccas appointed Eumenes governor of Cappadocia; but upon Ariarathes refusing to submit to Eumenes, Perdiccas made war upon him. Ariarathes was defeated, taken prisoner, and crucified, together with many of his relations, 322 BC. Eumenes then obtained possession of Cappadocia. Ariarathes was 82 years of age at the time of his death: he had adopted as his son Ariarathes II, the eldest son of his brother Holophernes.
| Preceded by Ariamnes |
Ruler of Cappadocia 331 BC – 322 BC |
Succeeded by Ariarathes II |