In the spring of 69 BC, Roman legions led by Lucullus invaded Armenia and advanced rapidly into the heart of the country. Tigran II the Great, who was on the southern fringes of his dominion, dispatched a three-thousand-strong cavalry unit under the command of his general Meruzhan to halt the enemy’s progress.
The Armenian cavalry, having covered a vast distance without rest, engaged in an uneven battle with the Romans, suffering heavy losses. In the battle, Meruzhan, the commanding officer, was killed.
Tigran II the Great urgently returned to Armenia with a six-thousand-strong guard unit and ordered his troops to follow him. Reaching Tigranakert, besieged by the Romans, Tigran’s guard infiltrated the city under the cover of night, breached enemy fortifications, and evacuated the royal family and treasury from the capital.
On October 6, 69 BC, a major battle took place near Tigranakert, in which the Romans forced the Armenian army to retreat. The siege of Tigranakert dragged on for several months. The treachery of Greek mercenaries and other foreign residents of Tigranakert, who opened the fortress gates, led to the fall of Armenia’s capital.
Having plundered and destroyed Tigranakert, Lucullus set his sights on capturing Armenia’s second capital, Artashat, and marched his legions north.
Meanwhile, Tigran II and Mithridates VI Eupator were recruiting and training new troops. Tigran adopted a new military strategy. Avoiding large-scale battles, Armenian detachments engaged in skirmishes to destroy small Roman units and disrupt the supply lines of the Roman army. This new tactic exhausted the enemy but did not stop their advance.
Lucullus persistently led his weary legions, motivating them with the promise of rich spoils awaiting them in “Armenian Carthage” — Artashat.
The threat of losing Artashat compelled Tigran II to engage in a decisive battle, which took place in September 68 BC, at a crossing on the Aratsani River.
The well-trained and organized Armenian army inflicted a defeat on the Romans. In the battle at Aratsani, the Romans suffered heavy losses and were forced to retreat from Armenia.
“And in this battle, the enemy cavalry put the Roman cavalry in a difficult position. Many were wounded, some killed, the crippled groaned, and at the same time there was a shortage of provisions, so Lucullus retreated…,” writes the Roman historian Lyon Cassius, thereby acknowledging the Roman defeat at Aratsani.
Building on this success, the Armenians expelled the Romans from the southern regions of their dominion — Mesopotamia.
At this time, Mithridates VI Eupator, with Armenian detachments, invaded Pontus and reclaimed his kingdom. Roman legionaries refused to fight against both Tigran II and Mithridates VI Eupator. The combined Armenian-Pontic forces forced the Romans into battle. In the ensuing battle in Pontus, the Roman legions suffered another heavy defeat. Dissatisfied with Lucullus’s actions, the Roman Senate relieved him of his command.
The situation favored the restoration of Tigran II the Great’s dominion, but the betrayal of his son, Tigran the Younger, who attempted to seize the throne, led to civil strife in Armenia and thwarted the king’s plans. The rebellion of Tigran the Younger was suppressed, and he fled to Parthia, where he found refuge.
The campaign of Lucullus in Armenia remains a testament to the resilience and strategic acumen of Tigran II the Great and his ability to defend his kingdom against formidable adversaries.
