Maximian

Maximian rose through the Roman army and was chosen by Diocletian first as Caesar and then, in 286, as co-Augustus with responsibility for the western provinces. He campaigned in Gaul, along the Rhine and in North Africa while Diocletian governed the eastern empire. In 305 both emperors abdicated as part of the planned succession of the Tetrarchy, but the settlement quickly broke down.

Maximian returned to imperial politics after his son Maxentius seized power in Rome in 306. His daughter Fausta married Constantine in 307, temporarily binding the rival houses together, but Maximian later tried to recover supreme power for himself. In 310 he rebelled against Constantine, withdrew to Massilia and died after the city surrendered.

In Ian Ross’s Swords Around the Throne, Maximian is a major historical figure whose renewed bid for power turns Constantine’s court and family connections into a direct threat to Aurelius Castus.