Maximian was Roman Emperor
Roman Emperor
The Roman emperor was the ruler of the Roman State during the imperial period . The Romans had no single term for the office although at any given time, a given title was associated with the emperor...

 from 286 to 305. He was Caesar
Caesar (title)
Caesar is a title of imperial character. It derives from the cognomen of Julius Caesar, the Roman dictator...

from 285 to 286, then Augustus from 286 to 305. He shared the latter title with his co-emperor and superior, Diocletian
Diocletian |latinized]] upon his accession to Diocletian . c. 22 December 244  – 3 December 311), was a Roman Emperor from 284 to 305....

, whose political brain complemented Maximian's military brawn. Maximian established his residence at Trier
Trier, historically called in English Treves is a city in Germany on the banks of the Moselle. It is the oldest city in Germany, founded in or before 16 BC....

 but spent most of his time on campaign. In the late summer of 285, he suppressed rebels in Gaul known as the Bagaudae
In the time of the later Roman Empire bagaudae were groups of peasant insurgents who emerged during the "Crisis of the Third Century", and persisted particularly in the less-Romanised areas of Gallia and Hispania, where they were "exposed to the depredations of the late Roman state, and the great...

. From 285 to 288, he fought against Germanic tribes along the Rhine frontier.

285    Diocletian appoints Maximian as Caesar and co-ruler.

285    Diocletian appoints Maximian as Caesar, co-ruler.

286    Roman Emperor Diocletian raises Maximian to the rank of ''Caesar''.

305    Diocletian and Maximian retire from the office of Roman Emperor.

307    After divorcing his wife Minervina, Constantine marries Fausta, the daughter of the retired Roman Emperor Maximian.

308    At Carnuntum, Emperor ''emeritus'' Diocletian confers with Galerius, ''Augustus'' of the East, and Maximianus, the recently returned former ''Augustus'' of the West, in an attempt to restore order to the Roman Empire.