Onesilus

Onesilus or Onesilos (Greek: Ὀνήσιλος; died 497 BC) was the brother of king Gorgos (Gorgus) of the Greek city-state of Salamis on the island of Cyprus. He is known through the work of Herodotus (Histories, V.104–115).

Cyprus was a part of the Persian Empire, but, when the Ionians rebelled from Persian rule, Onesilos captured the city of Salamis and usurped his brother’s throne. He was able to win over every city on the island except for the Graeco-Phoenician city-state of Amathus, which stayed loyal to the Persians.

In 497 BC, the Persians, with the help of the Phoenician navy, mounted an attack on Cyprus. Some of the Ionian colonies sent ships to assist Onesilos. In the ensuing battle, the Ionian fleet was able to defeat the Phoenician navy. Onesilos then led an army against the Persian general, Artybius. While Artybius was killed, the Persians won the battle during which Onesilos was killed. As a result, the Ionian fleet retreated from Cyprus and five months later, the Persians regained control of Cyprus. Onesilos’ brother, Gorgus Chersides, was then reinstated by the Persians as king of Salamis.

...
Wikipedia