Eumenes II
The date of his accession cannot be fixed with certainty; but it is certain, at least, that he was on the throne before 183 BC, in which year he succeeded in reducing the important city of Sinope, which had been long an object of ambition to the Kings of Pontus. The Rhodians sent an embassy to Rome to complain of this aggression, but without effect. About the same time Pharnaces became involved in disputes with his neighbour, King of Pergamon, Eumenes II, which led to repeated embassies from both monarchs to Rome, as well as to partial hostilities. But in the spring of 181 BC, without waiting for the return of his ambassadors, Pharnaces suddenly attacked both Eumenes II and King Ariarathes IV of Cappadocia and invaded Galatia with a large force.