Maximianus was born about A.D. 250. He served in the army with Diocletian, who, as emperor, appointed him Joint Augustus. Diocletian decided they should select their successors. Maximianus adopted Constantius as Caesar, and Diocletian adopted Galerius Maximianus. Years later, Maximianus` son, Maxentius, angry at being passed over, declared himself emperor. Maximianus tried to displace him, but failed. In A.D. 310, he tried to displace Emperor Constantine who had him strangled.