Farnobius was the optimatus (or chieftain) of one of the Greuthungi tribes, who were pressing on the Danubian frontier during the 370s as a result of westward pressure by the Huns. In 376, with the outbreak of the Gothic War, Farnobius led his people across the Danube from Muntenia, and poured into Moesia Secunda, together with two other Greuthungi tribes, led by Alatheus and Saphrax. Soon however, Farnobius broke away from the coalition, and proceeded to operate independently from the rest of the Greuthungi.
Farnobius’ tribe were soon joined by a group of Taifals, and they proceeded to ravage lower Moesia. In 377, Farnobius attacked a Roman castra at Beroea which was defended by the magister militum, Frigeridus. Frigeridus was forced to retreat from Thrace to Illyricum, where he managed to obtain reinforcements. He then returned to Thrace, moving through the mountains, where he surprised the troops of Farnobius, who were attempting to cross the same mountains. In the battle that followed, Farnobius was killed, and his troops captured.
- Ammianus Marcellinus, Rerum gestarum libri, Book 31, Chapter 9
- Heather, Peter, The Visigoths from the Migration Period to the Seventh Century: An Ethnographic Perspective, Boydell & Brewer Ltd (2003)
- Lenski, Noel Emmanuel, Failure of Empire: Valens and the Roman State in the Fourth Century A.D., University of California Press (2002)
- Martindale, J. R.; Jones, A. H. M, The Prosopography of the Later Roman Empire, Vol. I AD 260-395, Cambridge University Press (1971)
- Van Nort, Richard M., The Battle of Adrianople and the Military Doctrine of Vegetius (2007)
- Wolfram, Herwig; Dunlap, Thomas J., History of the Goths, University of California Press (1990)
- Van Nort, pg. 197
- Heather, pg. 46; Wolfram & Dunlap, pg. 92
- Wolfram & Dunlap, pgs. 119-120; Lenski, pg. 331
- Heather, pg. 47
- Lenski, pg. 334; Van Nort, pg. 201
- Van Nort, pg. 201
- Van Nort, pg. 202; Wolfram & Dunlap, pg. 123; Martindale, pg. 324
- Wirth, Gerhard, Rome and its Germanic Partners in the Fourth Century in Kingdoms of the Empire: The Integration of Barbarians in Late Antiquity (ed. Pohl, Walter) (1997), pg. 51