ALLECTUS, the prime minister and confidential friend of Carausius, emperor of Britain. In order to avoid the punishment due to the several enormous crimes with which he was chargeable, he fell upon the desperate expedient of murdering his master, and usurping the imperial dignity, which he maintained for three years. With the design of recovering Britain, the Cæsar Constantius despatched a portion of his fleet and army under the command of the pretorian prefect Asclepiodotus. The fleet of Allectus was stationed off the Isle of Wight to receive them; but under the cover of a thick fog, the invaders escaped their notice, and landed in safety on the western coast, and, according to Gibbon, convinced the Britons "that a superiority of naval strength will not always protect their country from a foreign invasion." In expectation of an attack from Constantius, who commanded the fleet off Boulogne, the usurper had taken his station in the vicinity of London; but informed of the descent of Asclepiodotus, he made forced marches to oppose his progress. In the battle which ensued Allectus was slain, and his forces received a total defeat; and thus Britain, after a separation of ten years, was restored to the Roman empire, A.D. 297.