
Caesar, with four legions, first began to build fortifications, assuming that Pharnaces had no taste for open battle against him, but he soon found this to be wrong. Separated by a valley a few miles apart, the two armies began to position for battle. The place had historical significance in that Pharnaces' father, Mithridates, had defeated a Roman army 20 years earlier. In May of 47 BC, Pharnaces camped his army on a hill near the town of Zela and Caesar on an opposite hill. Pharnaces took advantage and sought to delay Caesar as long as possible, hoping he would decide other matters were more urgent, but Caesar had lost patience. Marcus Antonius, appointed by Caesar as his master of horse (Caesar had been appointed to the dictatorship while in Egypt), was sent back to Rome to oversee administration of the city and was not living up to the task. Pharnaces at first agreed, but it was no secret that Caesar had pressing matters both in Rome and against hold-out Republican resistance elsewhere. Still, Caesar offered a peaceful solution, declaring that Pharnaces could be forgiven if he quit Pontus, released Roman prisoners, restored any financial damage done in the process, and of course, pay a hefty tribute. Despite the fact that Pharnaces was the only eastern king who remained neutral in the Roman civil war (as all other in the east had declared for Pompey) Caesar rebutted that only Pharnaces attacked Roman citizens, plundering and killing as he took advantage of the situation. Pharnaces meanwhile, well aware of Caesar's approach and his now notorious clemency, asked Caesar for a pardon of his own. Securing loyalty once again and laying out his plan of action, Caesar continued the march north to Pontus.

Boarding a ship in Syria, Caesar next sailed to Tarsus in Cilicia where he called a meeting of the regional leaders. In so doing, he was also able to rebuild his war chest through the various tributes paid to him. Heading towards the trouble with Pharnaces, Caesar traveled through Judaea and Syria, accepting apologies and granting pardons to those foreign kings and Roman governors who had supported Pompey. Meanwhile, Caesar was victorious in Egypt, and the lull back in Asia gave him the opportunity to relax on the Nile with Cleopatra.īy the campaign season of 47 BC, Caesar left Egypt and began an overland march through the far eastern provinces. In a fortunate turn of events, Pharnaces' appointed governor of Crimea revolted, allowing the Romans to recuperate in Asia Minor for the winter. Caesar's trouble in Egypt prompted him to request aid from King Mithridates of Pergamum, further depleting the potential resistance to Pharnaces, forcing Calvinus to make do. Calvinus gave battle and the Romans acquitted themselves well, but its allies were cut up badly. Caesar's legate, Gnaeus Domitius Calvinus, was installed as governor of Asia in the interim and did all he could to stop the Pontic advances, but had little success. The war in Alexandria delayed any immediate reaction, and his subsequent affair with Cleopatra occupied his attention for the seasonal winter months of 48 to 47 BC.

When Caesar defeated Pompey at Pharsalus in 48 BC, he still had no opportunity to deal with the Pharnaces situation. He began a systematic process of re-taking those lands which once belonged to his father's kingdom, and Rome or its allies could do little to stop it. Pharnaces II, king of Pontus, and son of the great Roman enemy Mithridates VI, used the Roman civil war to his advantage.
