- Allectus was Finance Minister to Carausius, usurper in Britain. In 293, as the forces of Constantius gathered across the Channel, Carausius was murdered and Allectus took his place.
- The invasion was launched in 296. Constantius took part of his fleet cruising off the coast of Kent awaiting safe entry to London. His praetorian commander, Asclepiodotus, sailed from the mouth of the Seine and dodging the fleet of Allectus, stationed off the Isle of Wight, in the fog, landed near Clausentum (near Winchester) and marched North.
- Allectus marched from London to meet him, but in a battle near Silchester (south of modern Reading), was defeated and killed. Evidence indicates that Silchester may have been looted by one force or the other.
- Meanwhile, Constantius had sailed up the Thames where, according to a gold medallion found near Arras in 1922, he was welcomed by Londinium as REDDITOR LVCIS AETERNA, the Restorer of the Eternal Light