Part of the agreement between Cinna and Sulla in their joint effort to grant citizenship to the Italians was that Sulla would be given command of several eastern legions, to prosecute war against Mithridates VI of Pontus. Mithridates, who took to the throne of his kingdom around 635 AUC (119 BC), had been working to expand the influence of his empire, meddling in the affairs of several other Anatolian states, such as Bythinia, Galatia, and Cappadocia. This was quite troubling for the Roman Republic, as those states were client states of Rome.
Sulla, eager for victory and glory, thus set out to combat Mithridates in 663 AUC (91 BC). Having previously been governor of Cilicia, he had some familiarity with both Pontus and Parthia, being the first Roman magistrate to have met with a Parthian ambassador. Mithridates, on the other hand, had been preparing for the inevitable conflict, forming an alliance with Tigranes the Great of Armenia, as well as securing assistance from other peoples along the Euxine (Black) Sea, such as the Dacians and Scythians.
|Coin depicting Mithridates VI of Pontus|
The war began with its first battle, in that same year. Sulla met Mithridates' forces near Nicomedia in Bithynia. The Pontic army was very elaborately equipped, with bright gold and silver armaments that shone brightly in the sun. Complimenting the traditional Macedonian phalanx was a contingent of scythe chariots. The entire army seems to have intimidated Sulla's legions, who hesitated to engage the enemy. Sulla thus set to work fortifying the Roman position. Eventually, their defenses were quite substantial and, more importantly, the legionaries were tired of digging. The battle began, and quickly turned in the Romans' favor. Sulla boasted in his own letters that over a 100,000 enemy soldiers were killed, to only 14 Romans missing in action (2 of which made their way back the next day). While his account is almost certainly unreliable, the battle was a resounding victory for Sulla's forces, and the Pontic army retreated back to their homeland.
Sulla then campaigned to the south, where another Pontic army had defeated the Cappadocians and threatened Roman coastal holdings. Again, the Romans were victorious by a significant margin. Cappadocia was secured and Sulla made preparations for a campaign into Pontus itself, to begin the next year. However, over the intervening winter, Mithridates made good on the bloody lessons his army had learned and put much effort into reforming the Pontic military, abandoning much of the Hellenistic elements and arms for Roman methods. He then launched a surprise attack, by sea, into Greece, hoping to distract Sulla from invading Pontus itself.
Mithridates' ploy worked, and Sulla was forced to meet the threat in Greece, in order to keep his supply lines from being threatened. However, the force in Greece was not the main component of the Pontic military, which had actually begun renewed assaults throughout the remaining Roman forces in Anatolia, honing their new army against the skeleton forces left behind. Lucius Julius Caesar (second cousin once removed to Gaius Julius Caesar), one of Sulla's commanders, was able to rally several contingents of Roman troops together, rather than be annihilated piecemeal. The Roman force, while still smaller, was able to hold its own against the Pontic army in a game of cat and mouse, stalling for time until Sulla could return.
Sulla's army eventually did return, early in the spring of 665 AUC (89 BC), and was able to combine his forces with the those under Caesar. The Romans then engaged Mithridates outside of Mazaka, in Cappadocia. The outcome of the battle was much more even than the initial engagement of the war, though, at the end, the Roman army held the field. Sulla then sent Caesar with a small contingent of troops to round the Anatolian Peninsula and invade Pontus by that route, while the main army would march straight through.
Sulla's strategy ended up succeeding, far better than he had intended. Caesar, marching his troops to port quickly and then, aided by favorable winds, reaching the Pontic coast much sooner than Sulla had expected him to, reached Mithridates' capital at Sinope several weeks ahead of Sulla's force. Entering the city by treachery, Caesar's army was able to capture Mithridates and his family. Sulla was thus deprived of the ultimate glory of victory.
Mithridates' son, Pharnaces II, was placed on the throne of a much reduced Kingdom of Pontus, subordinate to the Republic, and Sulla and Caesar returned to Rome for their triumph, which, much to Sulla's chagrin, was joint between the two generals. Sulla was officially awarded more honor for the victory, though, among the soldiers and populace, Caesar's daring campaign near the end earned him much prestige. Mithridates eventually died in Roman captivity, under unknown circumstances, either murder or suicide.
First and foremost, the Mithridatic War of this history has one key difference with the First Mithridatic War of our history: Marius is not alive to conspire against Sulla. Though I'm no fan of Sulla, he was put in a really tough situation by Marius and his supporters. Right after being sent out to defeat Mithridates, his command is stripped from him by a dubiously constitutional order. Thus set the stage for the first Roman general to march on Rome and take power by force. Hardly a good precedent, nor the precedent that Sulla himself wanted to set. Further, the ongoing struggle between Marius and Sulla, with bloody purges occurring each time one faction or the other happened to take back the city, served to both weaken the constitutional rule of law and distract Sulla from prosecuting his war with Mithridates.
In fact, a series of wars that ended up taking, eventually, decades to complete could have been accomplished in just one. Roman forces were very close to capturing Mithridates when Sulla was forced to make peace with him in order to restore order in Italia. With this nagging issue out of the way, the initial campaign is more focused and driven, allowing for a complete victory in only one war. While Mithridates was a relatively skilled leader and general, he was as often served well by sheer luck, and had a habit of biting off more than he could chew.
As for the battles, particularly the opening battle, I tried to stick as much as possible to the actual war of our history, while changing the actual locations around. Sulla really did make the outrageous casualty report about the first battle.