The ethnic affiliation of the Scordisci has been debated by historians. Some refer to them as Celtic, Thracian or Illyrian or a Celtic mix of the above. The Scordisci were found during different timelines in Illyria, Thrace and Dacia sometimes splitting into more than one group like the Scordisci Major and the Scordisci Minor.
Andras Mocsy clarifies their ethnic character, suggesting that they were not a Celtic tribe per se, but a "Celtic political creation". They were formed after 278 BC, as some of the survivors of the Celtic invasions of Greece settled the above-mentioned region imposing themselves as a thin, yet powerful, ruling class. Rather quickly, they were subsumed by the numerically superior natives, although the Celtic tribal name was retained, albeit the Illyricized versionScordistae was often used after the 2nd century BC. According to onomastic evidence, Scordiscan settlements to the east of the Morava river were Thracianized.
Extensive La Tène type finds, of local production, are noted in Pannonia as well as northern Moesia Superior, attesting to the concentration of Celtic settlements and cultural contacts. However, such finds south of the Sava river are scarce.
Despite the repulsion from Greece, Celtic power in the Balkans was certainly not at an end. After their formation c. 278 BC, little is heard of the Scordisci for some time. During Macedon's zenith, the attention of the Scordisci was focussed on Pannonia, consolidating their control of the region. They controlled the various Pannonian tribes in the region, extracting tribute and enjoying the status of the most powerful tribe in the central Balkans, and they erected fortresses in Singidunum and Taurunum (today's city of Belgrade). The Roman's first siege of Segestica, having been under the control of their Pannonian clients, curtailed Celtic control in Dalmatia and south-western Pannonia. This combined with the turmoil following Alexander the Great's death, prompted the Scordisci to turn their attention southward. They subjugated a number of tribes in Moesia, including the Dardani, several west Thracian tribes and the Paeonians.
Celtic tribes in the Balkans, c. 50 BC
In parts of Moesia (northeast Central Serbia) the Celtic Scordisci and Thracians lived beside each other, which is evident in the archeological findings of pits and treasures, spanning from 3rd century BC to 1st century BC.
From 141 BC, the Scordisci were constantly involved in battles against Roman held Macedonia. In 135 BC they were defeated by Cosconius in Thrace. In 118 BC, according to a memorial stone discovered near Thessalonica, Sextus Pompeius, probably the grandfather of the triumvir, was slain fighting against them near Stobi. In 114 BC they surprised and destroyed the army of Gaius Porcius Cato in the western mountains of Serbia, but were defeated by Minucius Rufus in 107 BC. Yet, they did not give up claim over Pannonia, since they are mentioned as having battled in the second siege of Sisak in 119 BC.
They still, from time to time, gave trouble to the Roman governors of Macedonia, whose territory they invaded in combination with the Maedi and Dardani. They even advanced as far as Delphi and plundered the temple; but Lucius Cornelius Scipio Asiaticus finally overcame them in 88 BC and drove them across the Danube. After this, the power of the Scordisci declined rapidly. This decline was more a result of the political situation in barbaricum rather than the effects of Roman campaigns, as their client tribes, especially the Pannonians, became more powerful and politically independent. Between 56 and 50 BC, the Scordisci were defeated by Burebista's Dacians, and became subject to him.
They were crushed in 15 BC by Tiberius, and became Roman subjects, playing the part as mercenaries. Other sources say the Romans made alliance with the Scordisci in Sirmium and Danube valleys following the Alpine campaign under Tiberius in 15 BC, the alliance would be crucial for the victory over the Pannonians (15BC) and later Breuci (12BC).They started receiving Roman citizenship during Trajan's rule. With their Romanization, they ceased to exist as an independent ethno-political unit.
^A History of Rome by Marcel Le Glay, Jean-Louis Voisin, Yann Le Bohec, and David Cherry, ISBN 1-4051-8327-6, 2009, page 101: "... 119-107 BCE Attacks on Macedonia's northern frontier by the Scordisci, a Thracian tribe who lived along the lower Save, were ..."
^Harry Thurston Peck, Harpers Dictionary of Classical Antiquities (1898), "Scordisci: A people in Pannonia Superior, are sometimes classed among the Illyrians, but were the remains of an ancient and powerful Celtic tribe. They dwelt between the Savus and Dravus."
^The Eastern Origin of the Celtic Nations Proved by a Comparison of Their Dialects with the Sanskrit, Greek, Latin, and Teutonic Languages: Forming a Supplement ... into the Physical History of Mankind by James Cowles Prichard, ISBN 0-543-79440-7, 2003, page 91), but only by arguing in a circle. The name Scordisci is from the mountain Scordus, and the Scordisci are Kelts. But this is just the ..."
^Wilkes, J. J. The Illyrians, 1992, ISBN 0-631-19807-5, Page 140, "... Autariatae at the expense of the Triballi until, as Strabo remarks, they in their turn were overcome by the Celtic Scordisci ..."
^Wilkes, J. J. The Illyrians, 1992, ISBN 0-631-19807-5, page 84: "...Celtic Scordisci away from the river Danube..."
^The Cambridge Ancient History, Volume 3, Part 2: The Assyrian and Babylonian Empires and Other States of the Near East, from the Eighth to the Sixth Centuries BC by John Boardman, I. E. S. Edwards, E. Sollberger, and N. G. L. Hammond, 1992, page 599, "...suggests that their origin is Serbo-Thracian rather than Illyrian..."
^The Cambridge Ancient History, Volume 3, Part 2: The Assyrian and Babylonian Empires and Other States of the Near East, from the Eighth to the Sixth Centuries BC by John Boardman, I. E. S. Edwards, E. Sollberger, and N. G. L. Hammond, 1992, page 599, "... formally describes them as Illyrians, but in the same passage he describes the Scordisci also as Illyrians. This opinion can be accounted for by ..."
^The Celts: a history by Dáithí Ó hÓgáin, 2003, page 60, "... element among the more numerous local populations of Thracians and Illyrians. The most powerful such new group of mixed Celts was the Scordisci..."
^Continuity and innovation in religion in the Roman West by R. Haeussler, Anthony C. King, Phil Andrews, 2007, ISBN 1-887829-67-9 "... have constituted the population of the Scordisci, divided into the Scordisci Maior west of the Velika Morava river and the Scordisci Minor east of it..."
^"Pannonia and Upper Moesia. A History of the Middle Danube Provinces of the Roman Empire. A. Mocsy. London and Boston, Routledge and Kegan Paul. ISBN 0-7100-7714-9. Pg 12 "the Scordisci ... are to be regarded merely one of the Celts' political creations and not as a Celtic tribe..."
^Strab. 7.3, "And mingled with them are also the Celtic tribes—the Boii, the Sorbisci, and the Taurisci. However, the Scordisci are by some called “Scordistae”; and the Taurisci are called also “Ligurisci” and “Tauristae.”"
^Mocsy. Pg 66 (referring to personal names) "...the names of the Scordici are south Pannonian- north Dalmatian, ie they have been Illyricized."
^Mocsy. Pg 26 "Recent excavations have produced La Tène finds in the northern part of Moesia Superior, in the territory of the Scordisci, in the southern part of this province, where the Scordisci were only temporarily in control, the influence of La Tène culture is not attested."
^Celts and the Classical World by David Rankin, ISBN 0-415-15090-6, 1996, page 188: "...of the survivors of Brenus expedition the Scordisci founded Singidunum in Yugoslavia..."
^The praetorship in the Roman Republic by T. Corey Brennan, 2000, page 229, "For his part, Cosconius campaigned successfully against the Scordisci..."
^The central Balkan tribes in pre-Roman times: Triballi, Autariatae, Dardanians, Scordisci and Moesians by Fanula Papazoglu, ISBN 90-256-0793-4, 1978, page 286, "As to where the battle between the Scordisci and Cosconius' troops took place,nothing definite can be said. The Scordisci had perhaps entered Thrace..."
^Rome's Mediterranean empire: books forty-one to forty-five and the Periochae by Livy, Jane D. Chaplin, 2007, page 268, "In Thrace, the praetor Marcus Cosconius fought successfully against the Scordisci..."
^Appian and Illyricum by Marjeta Šašel Kos, 2005, page 151, "A general who lost his life during an attack by the Scordisci is even epigraphically attested: the praetor Sextus Pompeius. His defeat is documented in..."
^Who's Who in the Roman World by John Hazel, 2002, ISBN 0-415-29162-3, "Cato 1, Gaius Porcius (C2 BC), was a grandson of CATO (4) and a supporter of the ... He was consul in 114 BC, when he lost a battle against the Scordisci in Macedonia..."
^The Cambridge Ancient History Volume 9: The Last Age of the Roman Republic, 146-43 BC by J. A. Crook, Andrew Lintott, and Elizabeth Rawson, 1994, ISBN 0-521-25603-8, Back matter, "M.Minucius Rufius over the Scordisci and the Thracians..."
^Dacia: Land of Transylvania, Cornerstone of Ancient Eastern Europe by Ion Grumeza, ISBN 0-7618-4465-1, 2009, page 51: "... Many Scordisci and Breuci settled in Dacia nevertheless and were eventually absorbed into the local population."
^Paterculus: The Tiberian Narrative (Cambridge Classical Texts and Commentaries) by Velleius Paterculus and A. J. Woodman, ISBN 0-521-60935-6, 2004, page 106, "...that in 12 B.C. Tiberius used the Scordisci tribe as allies, though in 16 they had been enemies pf Rome(54.20.3) .V. has already told us(39-3) that it was he who reconciled these natives to Rome presumably around 15 after his Alpine campaigns..."
^Tiberius (Blackwell Ancient Lives) by Robin Seager, ISBN 1-4051-1529-7, 2005, page 21, "Tiberius subdued Pannonia, making good use of a friendly tribe, the Scordisci."
^Wilkes, J. J. The Illyrians, 1992, ISBN 0-631-19807-5, Page 256, "... reign of Trajan (AD 98-117), does the Roman citizenship begin to appear among the Illyrian communities of southeast Pannonia, the Andizetes, Scordisci and Breuci."
^Wilkes, J. J. The Illyrians, 1992, ISBN 0-631-19807-5, page 145: "Autariatae had vanished long before the Roman conquest, and the Triballi, Scordisci and Moesi all declined to insignificant remnants, the Dardani endured."