Early in 313 Constantine and Licinius met at Milan, as we have seen in Chapter 4, and agreed on a common religious policy. They also, while not dividing the empire, agreed on their respective spheres of control. Licinius did not press a claim on Italy, which was rightfully his by virtue of his original appointment but which Constantine had seized from Maxentius. Licinius went on to eliminate Maximinus Daia and to campaign first on the Persian frontier and then against the Goths. Constantine went on to campaign on the Rhine frontier and to celebrate his decennalia. About July of 315 Constantia bore to Licinius a son who was named Valerius Licinianus Licinius; the birth of this child should have served further to strengthen the ties between the two emperors. In 312, 313 and 315 Constantine and Licinius jointly held the consulship, each for the second, third and fourth time respectively; in 314 they allowed two senators to serve as consuls. The Augusti appear together on some of the coins minted in these years. The senate, after the Battle of the Milvian Bridge, had designated Constantine as Maximus Augustus (senior Augustus), and he is thus referred to in some inscriptions. But the decorative programme of the Arch of Constantine suggests harmony and equality between the rulers, for they are there depicted no fewer than eight times in strict parallelism. Nevertheless the relationship between the two men was a strained one. Deep suspicions must have existed on both

sides, for both men had demonstrated by their past conduct that their ultimate goal was sole power. The agreement of 313 had been born of necessity, not of mutual good will. It was inevitable that hostilities eventually should erupt.