Bononia, a maritime town of Gallia Belgiea, now called Boulogue-surmer (Picardy). According to Peutinger 's table or map, its more ancients name was Gessoriacum, by which, however, historiens do not mention it, till the time of Constantine the Great. Their testimonies are given by Cellarius. But the most trustworthy record (says eckhel, |viii| 110), is that adduced from some anonymous biographer of Constantius Magnus, by D 'Anville. "Hastening towards his father (Contantius Chlorus), he arrived at Bononia, which the Gauls used to formerly call Gessoriacum." It was a place of great importance in a military point of view, bacause the transit thence to Britain across the straits is very short. According to Suetonius it was from this place that the emperor Claudius passed over into Britain, AD 43.