Based on the archaeological findings, the history of the Triballi can be divided in four periods: Proto-Triballian (1300-800 BC), Early Triballian (800-600 BC), Triballian (600-335 BC) and period from 335 BC until Roman conquest.
In 424 BC, they were attacked by Sitalkes, king of the Odrysae, who was defeated and lost his life in the engagement. They were pushed to the east by the invading Autariatae, an Illyrian tribe; the date of this event is uncertain.
In 376 BC, a large band of Triballi under King Hales crossed Mount Haemus and advanced as far as Abdera; they had backing from Maroneia and were preparing to besiege the city when Chabrias appeared off the coast, with the Athenian fleet, and organized a reconciliation.
In 339 BC, when Philip II of Macedon was returning from his expedition against the Scythians, the Triballi refused to allow him to pass the Haemus unless they received a share of the booty. Hostilities took place, in which Philip was defeated and wounded by a spear in his right thigh, but the Triballi appear to have been subsequently subdued by him.
After the death of Philip, Alexander the Great passed through the lands of the Odrysians in 335-334 BC, crossed the Haemus ranges and after three encounters (Battle of Haemus,
Battle at Lyginus river,
Battle at Peuce Island) defeated and drove the Triballians to the junction of the Lyginus at the Danube. 3,000 Triballi were killed, the rest fled. Their king Syrmus (eponymous to Roman Sirmium) took refuge on the Danubian island of Peukê, where most of the remnants of the defeated Thracians were exiled. The successful Macedonian attacks terrorized the tribes around the Danube; the autonomous Thracian tribes sent tributes for peace, Alexander was satisfied with his operations and accepted peace because of his greater wars in Asia.
They were attacked by Autariatae and Celts in 295 BC.
The punishment inflicted by Ptolemy Keraunos on the Getae, however, induced the Triballi to sue for peace. About 279 BC, a host of Gauls (Scordisci) under Cerethrius defeated the Triballi with an army of 3,000 horsemen and 15,000 foot soldiers. The defeat pushed the Triballi further to the east. Nevertheless, they continued to cause trouble to the Roman governors of Macedonia for fifty years (135 BC–84 BC).
The Illyrian Dardani tribe settled in the southwest of the Triballi area in 87 BC. The Thracian place names survives the Romanization of the region.
Pliny the Elder (23-79 AD) registers them as one of the tribes of Moesia.
In the time of Ptolemy (90–168 AD), their territory was limited to the district between the Ciabrus (Tzibritza) and Utus (Vit) rivers, part of what is now Bulgaria; their chief town was Oescus.
Under Tiberius, mention is made of Triballia in Moesia; and the Emperor Maximinus Thrax (reigned 235–237) had been a commander of a squadron of Triballi. The name occurs for the last time during the reign of Diocletian, who dates a letter from Triballis.