Northern Africa 294: Busiris–Coptos Revolt
Deciding that one emperor was insufficient to meet all the threats facing Rome, Diocletian appointed his deputy Maximian as Augustus (co-emperor) in 286 and then Constantius and Galerius as Caesars (junior emperors) seven years later. Galerius served directly under Diocletian, who sent him to deal with the revolt of the cities of Busiris and Coptos in Upper Egypt in c. 293–4.
? Jul 285–1 May 305 Reign of Diocletian▲
In 285 the 40-year-old Diocletian assumed complete control of the Roman Empire and the following year appointed his deputy Maximian as Augustus (co-emperor) to reign in the Western Empire, while Diocletian himself reigned on in the East. Over the next twenty years Diocletian vigorously reformed the empire, both by decentralization—he implemented the Tetrarchy (rule of two Augusti and two Caesars) in 293—and increasing bureaucracy and autocracy. In 305 he and Maximian stepped down in favor of the two Caesars, in an attempt to establish a precedent by becoming the first Roman emperor to retire voluntarily.
1 Apr 286–1 May 305 Co-reign of Maximian▲
In July 285 Diocletian appointed his slightly younger deputy Maximian as Caesar and the following year promoted him to Augustus (co-emperor). Diocletian took the title Jovius (after Jupiter) and ruled at Nicomedia in the East, while Maximian took the subordinate title Herculius (after Hercules) and ruled from Augusta Treverorum (Trier) in the West. In 293, with the implementation of the Tetrarchy, Maximian moved to Italy and appointed Constantius as his Caesar in Gaul and Britain. When Diocletian abdicated in favor of his own Caesar, Galerius, in 305, Maximian also stepped down, entering a reluctant retirement.
? ?? 289–10 Mar 298 Second Quinquegentiani War▲
In 289 the Quinquegentiani (“five peoples”), a confederation of Berber tribes in the highlands of Kabylia, launched a renewed rebellion against Roman rule in North Africa. Eventually, in 296, Maximian travelled to Africa to deal with the rebels and in the following years drove them back into the Atlas Mountains. By March 298, when Maximian celebrated his triumph in Carthage, the Romans had pushed the Quinquegentiani into the Sahara, after which they disappeared from history.
1 Mar 293 First Tetrarchy▲
In order to further secure both the Roman Empire and the succession, Diocletian presided over the appointment of two Caesars—Constantius to serve with Maximian in the West and Galerius to join Diocletian in the East. Both men, who had already proved themselves as loyal officers, divorced their current wives to marry the daughters of their superiors. For reasons unknown, Constantius was also given the title Jovius (Jupiter) and Galerius the inferior title Herculius (Hercules). This rule of four men—two Augusti and two Caesars—later became known as the Tetrarchy.
293?–294? Busiris–Coptos revolt▲
In the early 290s the Upper Egyptian cities of Busiris and Coptos revolted against Roman rule. Diocletian dispatched Galerius to deal with the situation. Galerius captured both cities and razed them to the ground in reprisal.