In the late 2nd Century BC, the Pontic king Mithridates VI Eupator began a campaign of expansion around the Black Sea and into the interior of Asia Minor in modern-day Turkey.

Mithridates in retaliation conquered Bithynia and Cappadocia once again and began massacring the Roman and Italic populations of Asia Minor with the assistance of the Greeks in what is referred to as the Asiatic Vespers.

He was to be attacked and defeated twice during this time, first by the Dardanians in an unknown location and then second near Histria by a coalition of Bastarnian and Scythian peoples, who may have been under the command of the Dacian king Burebista.

His rule led to a vast expansion of the Dacian kingdom, as far north as the Bug River at Olbia, south into Thrace, east along the Black Sea and west into Moesia and Pannonia.

[2] Mithridates VI began his career of military expansion first to the east, in modern-day Georgia, and soon after followed the coast of the Black Sea to the north.

[3] Mithridates' influence extended onto the north of the Black Sea and included the cities of Odessos, Nesebar, Histria (Istros), Tomis, Kallatis and Byzantion.

[5] Having subjugated Scythia, Mithridates turned his attention to the south and began conquering the neighbouring lands of Bithynia and Cappadocia while the Romans were embroiled in the Social War (91–88 BC), Rome attempted to force Mithridates into releasing the territory back to their respective kings urging the king of Bithynia to retaliate by invading Pontus and seizing loot to give to Rome.

During 89–88 BC Mithridates further expanded his territory by peacefully incorporating many Greek city-states within Asia Minor into his kingdom and Greece itself sought his assistance in freeing itself from Roman rule.

[1][3] In 88 BC, Mithridates had the Romans and Italic peoples residing in his kingdom and those that were within Asia Minor and Greece, including at Ephesus, Pergamon, Adramyttium, Caunus, Tralles and others, massacred in what is now called the "Asiatic Vespers".

[6] A few years later a Roman General Murena invaded Mithridate's land, sparking the Second Mithridatic War, in the Kizil Irmak River area.

Tigranocerta fell to the Romans during this campaign after a battle in the autumn of 69 BC, the following year Lucullus attempted to continue the subjugation of Armenia, however, his army was unprepared for the mountainous region and climate.

[9] Following this campaign, while Sulla returned to Rome, Hybrida remained behind with a small cavalry contingent to levy contributions from the province of Achaea.

This manoeuvre ultimately failed, however, as Hybrida and his men were surrounded by enemy infantry and forced out of the land losing all of the possessions that they had stolen.

[13][18] The Romans had been under the impression that with Mithridates defeat that the region had been conquered, however, while Hybrida and his men marched to occupy the city of Histria a large cavalry force of Bastarnae attacked them.

[28][29][30] To the north Burebista's campaigns led to the capture and control of the Greek merchant city of Olbia/Olbiopolis thus extending the border of the Dacian kingdom to the western bank of the Bug River.

[31] In Pannonia, the Dacians took over the fortified cities of Zemplin and Židovar and attacked the Celtic tribes that had expanded their lands towards the Black Sea.

The second war ultimately ended in the permanent defeat of the Dacians, the death of Decebalus and a large portion of Dacia being turned into a Roman province.