To proceed logically, let us suppose the absence of all kind of data. The only means to approach the truth would then be to adopt, as the place where Cæsar embarked, the port mentioned most anciently by historians; for, in all probability, the point of the coast rendered famous by the first expeditions to Britain would have been chosen in preference for subsequent voyages. Now, as early as the reign of Augustus, Agrippa caused a road to be constructed, which went from Lyons to the ocean, across the country of the Bellovaci and the Ambiani,[367] and was to end at Gesoriacum (_Boulogne_), since the Itinerary of Antoninus traces it thus.[368] It was at Boulogne that Caligula caused a pharos to be raised,[369] and that Claudius embarked for Britain.[370] It was thence that Lupicinus, under the Emperor Julian,[371] and Theodosius, under the Emperor Valentinian,[372] Constantius Chlorus,[373] and lastly, in 893, the Danes,[374] set sail. This port, then, was known and frequented a short time after Cæsar, and continued to be used during the following centuries, while Wissant and Calais are only mentioned by historians three or four centuries later. Lastly, at Boulogne, Roman antiquities are found in abundance; none exist at Calais or Wissant. Cæsar’s camp, of which certain authors speak as situated near Wissant, is only a small modern redoubt, incapable of containing more than 200 men. To this first presumption in favour of Boulogne we may add another: the ancient authors speak only of a single port on the coast of Gaul nearest to Britain; therefore, they very probably give different names to the same place, among which names figures that of _Gesoriacum_. Florus[375] calls the place where Cæsar embarked the port of the Morini. Strabo[376] says that this port was called _Itius_; Pomponius Mela, who lived less than a century after Cæsar, cites _Gesoriacum_ as the port of the Morini best known;[377] Pliny expresses himself in analogous terms.[378] Let us now show that the port of Boulogne agrees with the conditions specified in the “Commentaries.” 1. Cæsar, in his first expedition, repaired _to the country of the Morini, whence the passage from Gaul to Britain is shortest_. Now, Boulogne is actually situated on the territory of that people which, occupying the western part of the department of the Pas-de-Calais, was the nearest to England.