"Antenor potuit, mediis elapsus Achivis,
Illyricos penetrare sinus atque intima tutus
Regna Liburnorum, et fontem superare Timavi:
Unde per ora novem vasto cum murmere montis
It mare proruptum, et pelago premit arva sonanti.
Hic tamen ille urbem Patavi sedesque locavit
Teucrorum."
"Antenor having escaped from amidst the Greeks, could with safety penetrate the Illyrian Gulf and the inmost realms of Liburnia, and overpass the springs of Timavus, whence, through nine months, with loud echoing from the mountain, it bursts away, a sea impetuous, and sweeps the fields with a roaring deluge. Yet there he built the city of Padua and established a Trojan settlement."
The nearest proof at hand, that this is really the passage which was interpreted as referring to the ancient history of the Franks, is based on the following circumstances:
Gregorius of Tours had found in the history of Sulpicius Alexander accounts of violent conflicts, on the west bank of the Rhine, between the Romans and Franks, the latter led by the chiefs Markomir and Sunno (Greg., Hist., ii. 9).
From Gregorius, Gesta regum Francorum has taken both these names. According to Gesta, the Franks, under the command of Markomir and Sunno, emigrate from Pannonia, near the Mœotian marshes, and settle on the Rhine. The supposition that they had lived in Pannonia before their coming to the Rhine, the author of Gesta had learned from Gregorius. In Gesta, Markomir is made a son of the Trojan Priam, and Sunno a son of the Trojan Antenor.
From this point of view, Virgil's account of Antenor's and his Trojans' journey to Europe from fallen Troy refers to the emigration of the father of the Frankish chief Sunno at the head of a tribe of Franks. And as Gesta's predecessor, the so-called Fredegar, appeals to Virgil as his authority for this Frankish emigration, and as the wanderings of Antenor are nowhere else mentioned by the Roman poet, there can be no doubt that the lines above quoted were the very ones which were regarded as the Virgilian evidence in regard to a Frankish emigration from Troy.
But how did it come to be regarded as an evidence?
Virgil says that Antenor, when he had escaped the Achivians, succeeded in penetrating Illyricos sinus, the very heart of Illyria. The name Illyricum served to designate all the regions inhabited by kindred tribes extending from the Alps to the mouth of the Danube and from the Danube to the Adriatic Sea and Hæmus (cp. Marquardt Röm. Staatsverwalt, 295). To Illyricum belonged the Roman provinces Dalmatia, Pannonia, and Mœsia, and the Pannonians were an Illyrian tribe. In Pannonia Gregorius of Tours had located the Franks in early times. Thus Antenor, with his Trojans, on their westward journey, traverses the same regions from which, according to Gregorius, the Franks had set out for the Rhine.
Virgil also says that Antenor extended his journeys to the Liburnian kingdoms (regna Liburnorum). From Servius' commentary on this passage, the middle age knew that the Liburnian kingdoms were Rhetia and Vindelicia (Rhetia Vindelici ipsi sunt Liburni). Rhetia and Vindelicia separate Pannonia from the Rhine. Antenor, accordingly, takes the same route toward the West as the Franks must have taken if they came from Pannonia to the Rhine.
Virgil then brings Antenor to a river, which, it is true, is called Timavus, but which is described as a mighty stream, coming thundering out of a mountainous region, where it has its source, carrying with it a mass of water which the poet compares with a sea, forming before it reaches the sea a delta, the plains of which are deluged by the billows, and finally emptying itself by many outlets into the ocean. Virgil says nine; but Servius interprets this as meaning many: "finitus est numerus pro infinito."