Rome, the city, was now isolated and unimportant. Diocletian visited there only once because it was just too far from the action. The tetrarchs chose Trier, Milan, Thessalonica, and Nicomedia for their capitals.
By 304, Diocletian was old and sick. He decided to resign and convinced his partner to do likewise. The dual resignation date was May 1, 305. The two new emperors ascended to the throne and named their replacements as before, but the wrong people were passed over in the process. Severus and Maximinus were selected, but the sons of Constantius and Maximian – Constantine and Maxentius – were passed over. When Constantius died prematurely in 306, his army proclaimed Constantine as new emperor in the west. Before Galerius could elevate Severus in opposition, Maxentius proclaimed himself emperor in Rome. Ultimately, Constantine and Maxentius faced off in a battle at Milvian Bridge on October 28th, 312 with Constantine the winner. Maxentius drowned trying to cross the Tiber.