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 Caesars--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,
named Theodora, to whom coin 18 belongs.

Britain was now divided into four Diocletian provinces, to which a
fifth--Valentia--was later added when the country north of Hadrian's
wall was re-occupied. The only other event of Diocletian's reign to be
noticed is the persecution of Christians in which, according to
tradition, St. Alban lost his life at Verulam about 303.

(19-20) On May 1, 305, Diocletian and Maximian abdicated. Constantius
and Galerius now became Augusti. Trouble arose over the two vacant
Caesarships. It was the aim of Galerius to exclude Constantine, but the
latter escaped to his father's camp at York, a few weeks before
Constantius died on July 25, 306, after a victory over the Picts and
Scots. Constantine was in power under various titles in Gaul and
Britain for five years until, in 311, when Galerius died, he began his
march on Rome, during which he is said to have had his vision of the
cross with the words [Greek: en touto nika]. In 314 the bishops of
York, London, and some other uncertain British see attended the
Council of Arles which sat to deal with the Donatist schism. The
British Church was also represented at the Council of Nicaea, called by
Constantine in 325 to consider the Arian heresy, when the Nicene Creed
in its original form was autho