Bolgios was a Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

ish leader who led an invasion of Macedon

Macedon

Macedonia or Macedon was an ancient kingdom, centered in the northeastern part of the Greek peninsula, bordered by Epirus to the west, Paeonia to the north, the region of Thrace to the east and Thessaly to the south....

 and Illyria

Illyria

In classical antiquity, Illyria was a region in the western part of the Balkan Peninsula inhabited by the Illyrians....

 in 279 BC

279 BC

Year 279 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Saverrius and Mus...

, killing the Macedonian king Ptolemy Keraunos

Ptolemy Keraunos

Ptolemy Keraunos was the King of Macedon from 281 BC to 279 BC. His epithet Keraunos is Greek for "Thunder" or "Thunderbolt".He was the eldest son of Ptolemy I Soter, ruler of Egypt, and his third wife Eurydice, daughter of the regent Antipater. His younger half-brother, also called Ptolemy,...

.

He was part of a force of Gauls settled in Pannonia

Pannonia

Pannonia was an ancient province of the Roman Empire bounded north and east by the Danube, coterminous westward with Noricum and upper Italy, and southward with Dalmatia and upper Moesia....

 who had advanced to Thrace

Thrace

Thrace is a historical and geographic area in southeast Europe. As a geographical concept, Thrace designates a region bounded by the Balkan Mountains on the north, Rhodope Mountains and the Aegean Sea on the south, and by the Black Sea and the Sea of Marmara on the east...

 under a leader called Cambaules. Deciding on fresh conquests, they sent separate forces to different regions: one led by Cerethrius against the Thracians and Triballi; another against Paionia

Paionia

In ancient geography, Paeonia or Paionia was the land of the Paeonians . The exact original boundaries of Paeonia, like the early history of its inhabitants, are very obscure, but it is believed that they lay in the region of Thrace...

 led by Brennus

Brennus (3rd century BC)

Brennus was one of the leaders of the army of Gallic invasion of the Balkans, defeated the assembled Greeks at Thermopylae, and is popularly reputed to have sacked and looted Delphi, although the ancient sources do not support this.In 280 BC a great army, comprising about 85,000 warriors, coming...

 and Acichorius

Acichorius

Acichorius was one of the leaders of the Gauls, who invaded Thrace and Macedonia in 280 BC. He and Brennus commanded the division that marched into Paionia. In the following year, 279 BC, he accompanied Brennus in his invasion of Greece...

; and a third against the Macedonians and Illyrians, led by Bolgios.

The Macedonian king, Ptolemy Keraunos, was unconcerned by the approaching army, and declined an offer of 20,000 soldiers from the Dardanians

Dardani

Dardania was the region of the Dardani .Located at the Thraco-Illyrian contact zone, their identification as either an Illyrian or Thracian tribe is uncertain. Their territory itself was not considered part of Illyria by Strabo. The term used for their territory was , while for other tribes had...

. Bolgios sent ambassadors to Ptolemy, demanding payment to call off the attack. Ptolemy refused, instead demanding that the Gauls give him hostage

Hostage

A hostage is a person or entity which is held by a captor. The original definition meant that this was handed over by one of two belligerent parties to the other or seized as security for the carrying out of an agreement, or as a preventive measure against certain acts of war...

s and hand over their arms. Battle followed a few days later, where the Macedonians were severely defeated. Ptolemy was thrown by the elephant he was riding. He was captured and beheaded, and his head was paraded around the army on a spear.

The Gauls did not follow up their victory, and Sosthenes

Sosthenes of Macedon

Sosthenes was a Macedonian and general and may have been a king of the Antipatrid dynasty. During the reign of Lysimachus he was his governor in Asia Minor. Sosthenes was elected King by the Macedonian army, but he may or not have reigned as king. Appointed as Strategos he may have declined the...

, a Macedonian nobleman, took command, assembled an army and forced them to withdraw, although he was defeated by Brennus' contingent soon afterwards. The combined Gaulish army under Brennus and Acichorius then mounted an invasion of Greece, defeating a combined Greek army at Thermopylae and advancing to Delphi

Delphi

Delphi is both an archaeological site and a modern town in Greece on the south-western spur of Mount Parnassus in the valley of Phocis.In Greek mythology, Delphi was the site of the Delphic oracle, the most important oracle in the classical Greek world, and a major site for the worship of the god...

, where they were routed.