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.