Britannic Empire
The Britannic Empire of Carausius was a breakaway state in Roman Britain and on the northern coast of Gaul in 286–296. It was founded by Carausius, commander of the Channel fleet, who proclaimed himself emperor; in 293 his treasurer Allectus murdered and succeeded him. In 296 the forces of the Caesar Constantius Chlorus landed in Britain, Allectus was killed and the island returned to the empire.