The Battle of the Rhyndacis occurred in 73 or 72 B.C. between the Roman Republic

Roman Republic

The Roman Republic was the period of the ancient Roman civilization where the government operated as a republic. It began with the overthrow of the Roman monarchy, traditionally dated around 508 BC, and its replacement by a government headed by two consuls, elected annually by the citizens and...

an forces under Lucullus

Lucullus

Lucius Licinius Lucullus , was an optimate politician of the late Roman Republic, closely connected with Sulla Felix...

 and the army of the Kingdom of Pontus

Kingdom of Pontus

The Kingdom of Pontus or Pontic Empire was a state of Persian origin on the southern coast of the Black Sea. It was founded by Mithridates I in 291 BC and lasted until its conquest by the Roman Republic in 63 BC...

 as part of the Third Mithridatic War

Third Mithridatic War

The Third Mithridatic War was the last and longest of three Mithridatic Wars fought between Mithridates VI of Pontus and his allies and the Roman Republic...

.

Lucullus, based in Cilicia

Cilicia

In antiquity, Cilicia was the south coastal region of Asia Minor, south of the central Anatolian plateau. It existed as a political entity from Hittite times into the Byzantine empire...

, had foregone his planned invasion of Pontus from the south to come west and relieve his co-consul Marcus Aurelius Cotta, whom Mithridates had besieged at Cyzicus on the Sea of Marmara

Sea of Marmara

The Sea of Marmara , also known as the Sea of Marmora or the Marmara Sea, and in the context of classical antiquity as the Propontis , is the inland sea that connects the Black Sea to the Aegean Sea, thus separating Turkey's Asian and European parts. The Bosphorus strait connects it to the Black...

. Lucullus's five legion

Roman legion

A Roman legion normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. The organization of legions varied greatly over time but they were typically composed of perhaps 5,000 soldiers, divided into maniples and later into "cohorts"...

s began an effective counter-siege.

With the onset of winter, Mithridates sought to take advantage of a Roman feint against one of his outposts. He sent his sick, his wounded, and his cavalry east into Bithynia

Bithynia

Bithynia was an ancient region, kingdom and Roman province in the northwest of Asia Minor, adjoining the Propontis, the Thracian Bosporus and the Euxine .-Description:...

. In the middle of a snowstorm, Lucullus met these forces with ten cohorts along the banks of the Rhyndacus. Plutarch

Plutarch

Plutarch then named, on his becoming a Roman citizen, Lucius Mestrius Plutarchus , c. 46 – 120 AD, was a Greek historian, biographer, essayist, and Middle Platonist known primarily for his Parallel Lives and Moralia...

 and Appian

Appian

Appian of Alexandria was a Roman historian of Greek ethnicity who flourished during the reigns of Trajan, Hadrian, and Antoninus Pius.He was born ca. 95 in Alexandria. He tells us that, after having filled the chief offices in the province of Egypt, he went to Rome ca. 120, where he practised as...

 record 15,000 men and 6,000 horses as being captured during the battle.

Subsequently, Mithridates completely abandoned his position, sailing north while his army marched overland. Lucullus again routed them at the confluence of the Aesepus and Granicus Rivers.