GESORIACUM or BONO´NIA(Bouloyne), a place on the NW. coast of Gallia. Mela says (3.2): From the Osismii the face of the Gallic shore looks to the north, and reaches to the Morini, the remotest of the Gallic nations, and it contains nothing that is better known than the port Gesoriacum.This was the port from which the emperor Claudius embarked for Britain. (Suet, Claud. 100.17.) A road in the Antonine Itin. passes from Bagacum ( Bavay), through Castellum ( Cassel) and Taruenna ( Therouenne), to Gesoriacum. The Table has the same road, with the remark that Gesogiacum (Gesoriacum) was then called Bononia. Ptolemy (Ptol. 2.8.3) has Gesoriacum, a naval place of the Morini,between Portus Itius and the river Tabudas or Tabullas. But Boulogneis south of the Itius. Pliny (Plin. Nat. 4.16) makes the shortest passage from Gesoriacum to Britain to be 50 M. P.; which is too much, as D'Anville remarks, whether we measure to Doveror to Hythe, where he erroneously supposed that Caesar landed. But Pliny's measurement is probably made to Rutupiae ( Richborough), near Sandwich, where the Romans had a fortified post, and which was their landing-place from Gallia. This would make Pliny's distance nearer the truth, though still too much. Gesoriacum is also the Portus Morinorum Britannicumof Pliny (Plin. Nat. 4.23), as appears from his giving the length of Gallia to the Ocean along a line from the Alpes per Lugdunum ad portum Morinorum Britannicum.There was a district (pagus) round Gesoriacum, named from the town.
Dio Cassius (Dio Cass. 60.21) states that the Roman senate voted that a triumphal arch should be erected in honour of the emperor Claudius on the spot from which he sailed to Britain; and if this is true, it was erected at Boulogne, or that was the place where it was intended to be erected. D'Anville follows other writers in supposing that the Pharos or tower which Caligula erected on this coast, whence he menaced an invasion of Britain, was at Boulogne. (Suet. Calig. 100.45.) But there is no proof of this, except the fact of there having been an old tower at Boulognenear the sea up to the end of the seventeenth century. Eginhard, the biographer of Charlemagne, speaks of the emperor repairing this tower, and of its being an ancient construction.
Walckenaer ( GÉog., &c. vol. 1. p. 454) observes that there is no historical record of the name Gesoriacum being changed to Bononia; and he presumes that Bononia was the name of another part of the town, or of a town built on the other side of the port. This conjecture is confirmed by a passage of Florus (Flor. 4.12) which no commentator or editor has understood, and which has often been spoiled by corruptions more or less improbable.He reads the passage thus: Bononiam et Gessoriacum pontibus junxit, classibusque firmavit.But he does not say what authority he has for Bononia;and we have observed [GESONIA] that the other name is uncertain. Any person may see that Florus in this passage is speaking of the Rhine, and not of the coast. Besides, the notion of enumerating among the great exploits of Drusus the making bridges over the Liane, the small river of Boulogne, is rather ridiculous. This is not the only instance in which this laborious geographer has discovered what never existed. He adds that in the little place called Portel, at the foot of the hill of Boulogne, and half a league from the town, there were discovered, at the beginning of the 17th century, a large wall exceedingly hard, three pieces of marble seven feet long, and a sarcophagus of a single piece, well worked; all which he supposes to confirm his conjecture.
Bononia is named Oceanensis on a medal of Constans, to distinguish it from the Bononia of Italy. At this time the name Bononia was probably the only name used; and so Ammianus calls it (20.9), and Zosimus (6.2), who, however, speaks of it as a city of Lower Germania, though he knew it was on the coast. Constantine passed over from Britain to Bononia, and this was probably the regular landing-place from Britain since the time of Claudius. It appears, indeed, as the naval station on this coast, for Carausius was set over the fleet at Bononia to protect the Belgic and Armoric shore against the Franks and Saxons. (Eutrop. 9.21.)
There are no Roman buildings at Boulogne. The tower, already mentioned, is entirely gone. It was no doubt a Roman work. Within the present century Roman medals and tombs have been discovered at Boulogne, and other remains.
[G.L]