have been to diminish the embarrassment of defeat. Diocletian curtailed his Eastern province tour soon after, perhaps on learning of Maximian's failure. Diocletian returned in haste to the West, reaching Emesa by 10 May 290, and Sirmium on the Danube by July 1, 290. Diocletian met Maximian in Milan either in late December 290 or January 291. Crowds gathered to witness the event, and the emperors devoted much time to public pageantry. Potter, among others, has surmised that the ceremonies were arranged to demonstrate Diocletian's continuing support for his faltering colleague. The rulers discussed matters of politics and war in secret, and they may have considered the idea of expanding the imperial college to include four emperors (the Tetrarchy). Meanwhile, a deputation from the Roman Senate met with the rulers and renewed its infrequent contact with the imperial office. The emperors would not meet again until 303. Following Maximian's failure to invade in 289, an uneasy truce with Carausius began. Maximian tolerated Carausius' rule in Britain and on the continent but refused to grant the secessionist state formal legitimacy. For his part, Carausius was content with his territories beyond the Continental coast of Gaul. Diocletian, however, would not tolerate this affront to his rule. Faced with Carausius' secession and further challenges on the Egyptian, Syrian, and Danubian borders, he realized that two emperors were insufficient to manage the Empire. On March 1, 293 at Milan, Maximian appointed Constantius to the office of Caesar. On either the same day or a month later, Diocletian did the same for Galerius, thus establishing the "Tetrarchy", or "rule of four". Constantius was made to understand that he must succeed where Maximian had failed and defeat Carausius. Campaign against Allectus Constantius met expectations quickly and efficiently and by 293 had expelled Carausian forces from northern Gaul. In the same year, Carausius was assassinated and replaced by his treasurer, Allectus. Constantius marched up the coast to the Rhine and Scheldt estuaries where he was victorious over Carausius' Frankish allies, taking the title Germanicus maximus. His sights now set on Britain, Constantius spent the following years building an invasion fleet. Maximian, still in Italy after the appointment of Constantius, was apprised of the invasion plans and, in mid-296, returned to Gaul. There, he held the Rhenish frontiers against Carausius' Frankish allies while Constantius launched his invasion of Britain. Allectus was killed on the North Downs in battle