PANNONIA, in ancient geography a country bounded north and east by the Danube, conterminous westward with Noricum and upper Italy, and southward with Dalmatia and upper Moesia. It thus corresponds to the south-western part of Hungary, with portions of lower Austria, Styria, Carniola, Croatia, and Slavonia. Its original inhabitants (Pannonii, sometimes called Paeonii by the Greeks) were probably of Illyrian race. From the 4th century B.C. it was invaded by various Celtic tribes, probably survivors of the hosts of Brennus, the chief of whom were the Carni, Scordisci and Taurisci. Little is heard of Pannonia until 35 B.C., when its inhabitants, having taken up arms in support of the Dalmatians, were attacked by Augustus, who conquered and occupied Siscia (Sissek). The country was not, however, definitely subdued until 9 B.C., when it was incorporated with lUyria, the frontier of which was thus extended as far as the Danube. In A.D. 7 the Pannonians, with the Dalmatians and other Illyrian tribes, revolted, and were overcome by Tiberius and Germanicus, after a hard-fought campaign which lasted for two years. In A.D. 10 Pannonia was organized as a separate province — according to A. W. Zumpt (Studia romana), not till A.D. 20; at least, when the three legions stationed there mutinied after the death of Augustus (A.D. 14), Junius Blaesus is spoken of by Tacitus (Annals, i. 16) as legate of Pannonia and commander of the legions. The proximity of dangerous barbarian tribes (Quadi, Marcomanni) necessitated the presence of a large number of troops (seven legions in later times), and numerous fortresses were built on the bank of the Danube. Some time between the years 102 and 107, which marked the termination of the first and second Dacian wars, Trajan divided the province into Pannonia superior (ἡ ἅνω), the western, and inferior (ἡ κάτω), the eastern portion. According to Ptolemy, these divisions were separated by a line drawn from Arrabona (Raab) in the north to Servitium (Gradiska) in the south; later, the boundary was placed farther east. The whole country was sometimes called the Pannonias (Pannoniac). Pannonia superior was under the consular legate, who had formerly administered the single province, and had three legions under his control: Pannonia inferior at first under a praetorian legate with a single legion as garrison, after Marcus Aurelius under a consular legate, stll with only one legion. The frontier on the Danube was protected by the establishment of the two colonies Aelia Mursia (Esse) and Aelia Aquincum (Alt-Ofen, modern Buda) by Hadrian.
Under Diocletian a fourfold division of the country was made. Pannonia inferior was divided into (i) Valeria (so called from Diocletian's daughter, the wife of Galerius), extending along the Danube from Altinum (Mohacs) to Brigetio (Ó-Szöny), and (2) Pannonia sccunda, round about Sirmium (Mitrovitz) at the meeting of the valleys of the Save, Drave, and Danube. Pannonia superior was divided into (3) Pannonia prima, its northern, and (4) Savia (also called Pannonia ripariensis), its southern part. Valeria and Pannonia prima were under a praeses and a dux; Pannonia secunda under a consularis is and a dux; Savia under a dux and, later a corrector. In the middle of the 5th century Pannonia was ceded to the Huns by Theodosius II., and after the death of Attila successively passed into the hands of the Ostrogoths, Longobards (Lombards), and Avars.
The inhabitants of Pannonia are described as brave and warlike, but cruel and treacherous. Except in the mountainous districts, the country was fairly productive, especially after the great forests had been cleared by Probus and Galerius. Before that time timber had been one of its most important exports. Its chief agricultural products were oats and barley, from which the inhabitants brewed a kind of beer named sabaea. Vines and olive-trees were little cultivated, the former having been first introduced in the neighbourhood of Sirmium by Probus. Saliunca (Celtic, nard) was a common growth, as in Noricum. Pannonia was also famous for its breed of hunting-dogs. Although no mention is made of its mineral wealth by the ancients, it is probable that it contained iron and silver mines. Its chief rivers were the Dravus (Drave), Savus (Save), and Arrabo (Raab), in addition to the Danuvius (less correctly, Danubius), into which the first three rivers flow.
The native settlements consisted of pagi (cantons) containing a number of vici (villages), the majority of the large towns being of Roman origin. In Upper Pannonia were Vindobona (Vienna), probably founded by Vespasian; Carnuntum (q.v., Petronell); Arrabona (Raab), a considerable military station; Brigetio; Savaria or Sabaria (Stein-am-Anger), founded by Claudius, a frequent residence of the later emperors, and capital of Pannonia prima; Poetovio (Pettau); Siscia, a place of great importance down to the end of the empire; Emona (Laibach), later assigned to Italy; Nauportus (Ober-Laibach). In Lower Pannonia were Sirmium, first mentioned in A.D. 6, also a frequent residence of the later emperors; Sopianae (Fiinfkirchen), seat of the praeses of Valeria, and an important place at the meeting of five roads; Aquincum, the residence of the dux of Valeria, the seat of legio ii adjutrix.
See J. Marquardt, Römische Staatsverwaltung, i. (2nd ed., 1881), 291; Corpus inscriptionum latinarum, iii. 415; G. Zippel, Die romische Herrschaft in Illyrien (Leipzig, 1877); Mommsen, Provinces of the Roman Empire (Eng. trans.), i. 22, 38; A. Forbigur, Handbuch der alten Geographie von Europa (Hamburg, 1877); article in Smith's Dictionary of Greek and Roman Geography, ii. (1873); Ptolemy, ii. 15, 16; Pliny, Nat. Hist. ii. 28; Strabo vii. 313; Dio Cassius xlix. 34-38, liv. 31-34, lv. 28-32; Veil Pat. ii. 110.