It was spring 82 BC. Lucius Licinius Murena and his two Fimbrian legions and auxiliaries
set up camp at the slope of a hill. They had been trekking north along the Halys river,
raiding any settlement they came across. Their goal was to reach the Black Sea Coast
and seize Pontic territory. Across the river, another fire burned. A small expeditionary army
under Pontic general Gordius had been trailing the Romans for days.
Both sides were aware of each other, but neither side attacked thus far. Gordius sent messengers
to his King to keep him up to date about the Roman positions. Though plunderings and minor skirmishes
preceded this moment, the impending battle would be the largest of the Second Mithridatic War.
[The Battle of Halys, 82 BC | Second Mithridatic War]
The First Mithridatic War came to a climactic end with the 85 BC Peace of Dardanus,
resembling a truce. This truce, however, was mutually beneficial to Roman commander Lucius
Cornelius Sulla and King Mithridates of Pontus. Sulla certainly had different matters to attend,
namely the ever-escalating civil war in Italy. Sulla returned to Rome and left Lucius Licinius
Lucullus to reorganise the Roman military on Asia Minor. First, he separated Fimbria's
former soldiers, two legions in total. These veterans were placed under Murena's command,
one of Sulla's most trusted commanders who accompanied him during his Greek campaign in
the previous war. Murena set up headquarters in Cappadocia, just south of the River Halys.
As for Mithridates, the King finally had some breathing room to reflect on his situation,
past mistakes and the loss of 160.000 soldiers. He understood the danger of Sulla losing his
civil war: the truce would be nullified, and he would once again face Rome's might.
One of his first acts after Sulla returned to Rome was to pacify the troubled territories he still
had. He easily financed this as he looted his lost territories upon his retreat. Before too long,
Mithridates again possessed a mighty mercenary army. He also bankrolled pirates who pestered
the seas from the Aegean all the way to the coast of the Iberian Peninsula, where Quintus Sertorius
led a large-scale rebellion against Sulla. Meanwhile, Ariobarzanes of Cappadocia
had lost and regained his throne more times than he could count. Still, his position wasn't stable,
and Mithridates decided to encroach on the Cappadocian periphery. But, when confronted,
he denied it and continued the practice. Having learned from his previous disastrous
defeat, Mithridates realised he should do things himself if he wanted to do them right.
So, besides attracting new troops, he also changed the basis of his army. Instead of the phalanx,
now twice beaten by Roman infantry, he spent lavishly expanding his cavalry and archery units.
Plutarch wrote about this: "Instead of an inefficient army which made a good show but
was less than useful...he knocked his forces into a leaner, more serviceable shape...gone
were the mixed multitudes and howling threats of barbarian tribes with their jewelled ornaments
of gold which the enemy found more tempting than threatening. Now the men were armed and
formed up in Roman style, with horses better suited for service than show."
Of course, the King wanted to put this new lean force into practice. The region which
gave him the biggest headache was his Black Sea territory, namely Colchis and the Bosphorus.
So he dispatched his son, Mithridates Philopater, as the governor. Hoping his son would re-establish
order, the young man was a bit too successful. The King suspected he was planning a coup
and the unrest in Bosphorus was a deliberate ploy to exert control.
What followed reveals a lot about Mithridates as a person.
First, he had his son brought back to Pontus in golden chains. Then, upon his arrival,
he sentenced him to death for his overambitious reign. After dealing with one son, Mithridates
repeated his trusted recipe. With the new army, he dispatched another son,
Menchares, as governor of the region. Keeping these positions within the family
was a significant diversion from his previous tactics of appointing able generals. Although,
after losing 160.000 soldiers, Mithridates rightly doubted whether they were able.
[Archelaus' Betrayal]
The personification of his previous military disasters was Archelaus. With Mithridates' recent
appointments, it became clear he was not planning on letting Archelaus lead him to a third disaster.
The general caught rumours of Mithridates doubting whether he had been too
lenient when negotiating peace with Sulla. Archelaus' gut feeling was that his days were
numbered. Instead of waiting for his demise, the until then loyal general did the unthinkable. He
deserted to Murena and his Fimbrians. He provided false intel to Murena, stating Mithridates planned
to deploy his new army against him at any time. Considering Mithridates indeed just raised a
massive army, it was nothing short of bad luck that around this time, Murena realised it was
easier to control the Fimbrians in war than in peace. Not to mention the prestige he would attain
if he emerged victorious from the conflict. So the Roman commander figured the best way to keep them
occupied was to act on Archelaus' rumours, completely disregarding the concluded peace.
Without waiting for orders from Rome, Murena and his Fimbrians invaded Pontus somewhere in late
83 BC. At Comana, his legions plundered houses, bazaars and temples. Because Pontus harboured
most of Asia Minor's looted riches from the aftermath of the previous war, Murena's legions
could not believe the wealth they acquired. News reached Mithridates of his southern
border being plundered. He dispatched a cavalry detachment to investigate,
unsure of what to expect. When only a fraction of his horsemen returned, relaying how the Romans
slaughtered the rest of them, he was confused but not necessarily surprised by the hostilities.
He dispatched an envoy to tell Murena this violated the truce with Rome.
Murena was sympathetic to Mithridates' demands. He told the King that he would withdraw if he could
show the peace terms in writing. Murena was well aware the truce was verbal rather than written.
The diplomatic negotiations did buy Mithridates enough time for the campaigning season to end.
He spent the winter raising a fresh army for a campaign against the Roman invaders.
As winter turned into spring, Murena beat the conventional time frame of the campaigning season.
He crossed the Halys River earlier than expected, and ancient sources report his men plundering 400
towns. Mithridates did not intervene against the plundering, and Murena retreated to Phrygia.
As raids continued in Asia Minor, Sulla emerged victorious in the power struggle on the Italian
peninsula. Frustrated about the unrest in the east, he dispatched an envoy to tell Murena off.
But as soon as the envoy departed, Murena invaded Pontus again. Whether he acted against Sulla's
orders or secretly received the green light to continue pestering Mithridates is unknown.
This time Murena moved along the Halys, and it became clear he was pushing all the way
north to Sinope. He travelled along the banks of the Halys, plundering settlements in his
way. News reached Mithridates, who reasoned Rome had officially declared war against him,
which in fact was not the case. This time the King was prepared.
First, he dispatched his general Gordius with the explicit order to trail Murena's
army and keep him in the loop. Then, he began gathering his army to expel the intruders.
Murena and his soldiers marched along the Halys river. The trek to their target, Sinope, was still
days away. He commanded the Fibrians, divided into two legions. They numbered anywhere between 5100
and 11000 fighting men, including auxiliaries. The auxiliaries consisted of conscripted Bithynians,
Galatians and Cappadocians. A more realistic estimate of the size of the Fimbrian Legions
would be roughly 5500 soldiers per legion. This meant the total force Murena commanded numbered
around 11000 soldiers, including auxiliaries. It is more than likely a minor Equites unit
or cavalry accompanied the Romans. They would not have numbered anywhere over 600.
Gordias commanded a minor vanguard army, closely monitoring the Roman movement from across the
river. Both sides were aware of the presence of each other. Gordius did not act, understandably
so because he was outnumbered. Instead, his men set up camp in the mountainous terrain,
which would be difficult for Murena's entire army to collapse on, and continued trailing them. There
is no clear indication why Murena did not surround Gordius or dispatch small units to get rid of him.
All that is known is that Gordius kept Mithridates up-to-date on their
whereabouts. In the meantime, the King rode ahead of his main army towards the river.
Once Mithridates arrived, the Pontic army at least matched the Romans in size if not outsize them.
This was the first time any Romans faced a Pontic army since the Battle of Orchomenos.
As such, it must have been quite a surprise to them when they realised Mithridates' army makeup
was vastly different from before. Though not conclusive,
sources indicate the traditional phalanx was left out. Instead,
most of his troops were cavalry and archers - traditional weaknesses of Roman infantry.
[Battle sequence]
Mithridates did not grant the Romans much time to be surprised. As soon as he noticed
Murena across the river, he ordered his army to charge forward. A huge cavalry charge followed,
with archers trying to keep up with the main army. Even without archery support,
the cavalry swept the unprepared Fimbrians. Some put up a fight, while Murena ordered most of his
infantry to retreat to strategic higher ground. Ferocious fighting continued between those who
kept the cavalry at bay, allowing the rest to withdraw. Vastly outnumbered, the Roman
infantry did not stand a chance. They held the cavalry back until there was nobody left to fight.
Clearing out the initial Roman units, the cavalry now mounted a second charge. Despite the charge
being uphill, they came at the Romans rapidly. Murena, though on strategic higher ground, did not
have enough time to organise his army, let alone have them take defensive positions. The Pontic
cavalry was ruthless, as they slew many soldiers who could not getaway. By the time the archers
caught up, all they could do was help the cavalry finish the job of the few Romans who were alive.
Murena and several of his commanders fled into the mountains, pestered by missiles of Pontic archers
chasing them. It took them a while to reach safe ground again. They likely spent multiple days,
if not weeks trekking through the rough, occasionally uncharted mountains of Phrygia.
Mithridates felt good. He commanded the army himself. This was only the third time in over
four decades of being King. After defeating the Fimbrians, he began organising a further invasion
against Cappadocia and territories in the west. By this time, Mithridates invaded and lost
Cappadocia more times than he could count. He awarded himself a significant chunk of territory
as compensation for his trouble. He made plans to push forward his invasion. Instead,
a more senior Roman envoy met him before he could. The envoy told him Sulla honestly did not want
war. Sulla had ordered Murena to return to Rome and retire on his plot of land. He then arranged
a marriage between Mithridates' daughter and Ariobarzanes, the man who was crowned Cappadocian
King enough times to raise many eyebrows. After the marriage, Mithridates rewarded himself
with another chunk of Cappadocian territory. After just one battle, the Second Mithridatic War came
to an unsatisfactory end. The peace didn't restore relations between Rome and Pontus, let alone
stability in the region. However, Mithridates did extend his territory and polished his reputation
as a protector against raiding Romans. It would be several years until the third and final
Mithridatic War broke out. It was to become the longest war between Rome and Pontus yet.