293 Consul IV (with Diocletian V); First Tetrarchy: Galerius and Constantius I Chlorus proclaimed caesares; all four men accept the title Germanicus Maximus, Maximianus for the fourth time; in Britain, Carausius is killed by Allectus
294 Diocletian defeats the Sarmatians; Maximianus accepts the title Sarmaticus Maximus II
Milestone of Maximian
295 Galerius fight against the Persians (?); Maximianus accepts the title Persicus Maximus
296 Diocletian fights against the Carpi; Maximianus accepts the title Carpicus Maximus and adds Britannicus Maximus after Constantius has reconquered Britain
296/297 Insurrection of Julianus in Africa; campaign against the Moors
297 Consul V (with Galerius II)
298 Stay in Carthage and expedition to Tripolitana; Galerius defeats Narseh; end of the Persian war; Maximianus accepts the titles Armeniacus Maximus, Medicus Maximus, Adiabenicus Maximus, and Persicus Maximus II
299 Consul VI (with Diocletian VII); return to Rome; begins building the Baths of Diocletian
300 Accepts, after Galerius' successes along the Danube, the title Sarmaticus Maximus III
301 Accepts, after Constantius' successes along the Rhine, the title Germanicus Maximus V; monetary reform; edict on Maximum Prizes
303 Consul VII (with Diocletian VIII); joint triumph with Maximianus; edict against the Christians
304 Consul VIII (with Diocletian IX)
305 Diocletian and Maximianus resign; Second Tetrarchy: they are succeeded by Galerius and Constantius I Chlorus, who appoint as caesares Maximinus Daia and Severus II
Maximianus retires from politics
Main deeds, second reign
306 Third Tetrarchy: After the death of Constantius I Chlorus, Severus II becomes emperor and recognizes Chlorus' son Constantine as his caesar. Maxentius, the son of Maximianus, occupies Rome, demanding the caesarship; Maximianus supports him
307 In Ravenna, Maximianus forces Severus II into surrender and orders him to abdicate;note[Zosimus, New History 2.10.1-2.] recognizes Constantine as emperor, marries him to his daughter Fausta; consul IX (with Constantine)
308 Maximianus unsuccessfully tries to dethrone his son in Rome; flees to Constantine; Conference at Carnuntum; Maximianus persuaded to resign again
310 Maximianus provokes a new rebellion, is captured, and reportedly commits suicide