After the death of Philip, Alexander the Great passed through the lands of the Odrysians in 335-334 BC, crossing the Haemus ranges and after three encounters (including the Battle of Haemus) defeated and drove the Triballians to the junction of the Lyginus at the Danube. Around 3,000 Triballi were killed, the rest fled. Syrmos and his people took refuge on the Danubian island of Peukê where most of the remnants of defeated Thracians were exiled. The successful Macedonian attacks terrorized the tribes around the Danube, so the autonomous Thracian tribes sent tributes to Alexander seeking peace. Alexander was satisfied with his victories and accepted peace so he could focus on the battles ahead in Asia.
- Plutarch's Lives by Plutarch, 2008, ISBN 1-4404-1432-7, page 183: "... Danube, and by winning a signal victory over Syrmus, the King of the Triballi. After this, as he heard that the Thebans had revolted, ..."
- Papazoglu 1978, p. 73.
- Heckel, W. (2006). Who's Who in the Age of Alexander the Great: Prosopography of Alexander's Empire. Wiley. p. 258. ISBN 9781405112109. Retrieved 2014-11-23.
- Gebhardi, L.A. (1778). Geschichte des Reichs Hungarn und der damit verbundenen Staaten. p. 75. Retrieved 2014-11-23.
- Papazoglu, p. 74
- Papazoglu, Fanula (1978). The Central Balkan Tribes in pre-Roman Times: Triballi, Autariatae, Dardanians, Scordisci and Moesians. Amsterdam: Hakkert.
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