Antoninianus - Carausius Mars

Carausius seized control of Britain and northern Gaul in 286 after being ordered executed by Maximian — ostensibly for embezzling recovered pirate loot, though the charge was almost certainly political. Rather than submit, he declared himself Augustus and ran a remarkably functional breakaway state for seven years, issuing coinage of a quality that shamed the contemporary output of the legitimate tetrarchic mints. His bronzes frequently carry better silver wash than anything Rome was producing at the time.

The Colchester and London mints struck the bulk of his output. London's mint mark, ML or MLXXI, helps distinguish issues by workshop within the reign.