(11) Postumus at once had to face a great invasion of Franks. He
gained some successes and was therefore proclaimed emperor by the
armies of Gaul and Britain. Before long dissensions broke out in the
Gallic empire and several commanders rose and fell in rapid
succession. It is conceivable that some of these are represented in
the coins found in Blackbanks, but these specimens are too badly
weathered for certain identification to be possible.

(12) On March 4, 268, Gallienus was assassinated. His successor was M.
Aurelius Claudius, afterwards surnamed Gothicus, a skilful general who
did the empire great service by his victories over invaders from
Switzerland and the Tyrol by the shores of the Lago di Garda, and over
the Goths at Naissus (Nish).

(13) Tetricus is of interest only because his surrender to Aurelian in
273 marks the collapse of the Gallic empire.

(15-18) Diocletian became Augustus in 284, and co-opted Maximian as
his colleague two years later. About the same time Carausius,
commander of the Channel fleet, crossed to Britain and had himself
proclaimed independent emperor. In 290 he was acknowledged as third
colleague by the Augusti, but no place was found for him when in 293
the government of the Roman world was divided between Diocletian,
Maximian, and two newly chosen Cæsars--Galerius and Flavius Valerius
Constantius, later called Chlorus. By this arrangement the recovery of
Britain from Allectus--who had murdered Carausius about 294--fell to
Constantius, and he accomplished this by a sudden attack in 296.
Constantius was twice married. His first wife, Helena, bore him a son,
Constantine the Great; his second was a step-daughter of Maximian,