 Constantius Chlorus’ first task on becoming Caesar was to deal with the Roman usurper Carausius who had declared himself emperor in Britannia and northern Gaul in 286.In late 293, Constantius defeated the forces of Carausius in Gaul, capturing Bononia (Boulogne-sur-Mer).This precipitated the assassination of Carausius by his "rationalis" Allectus, who assumed command of the British provinces until his death in 296.