Bayan Diocletian ya sauka a ranar 1 ga Mayu, 305, magajinsa sun fara gwagwarmaya don kula da Daular Roma kusan nan da nan. Ko da yake Constantine shi ne dan yammacin Sarkin sarakuna Constantius, ra'ayin Tetrarchic ba lallai ba ne ya ba da damar maye gurbin gado. Lokacin da Constantius ya mutu a ranar 25 ga Yuli, 306, sojojin mahaifinsa sun yi shelar Constantine a matsayin Augustus a Ebora (York). A Roma, wanda aka fi so shi ne Maxentius, ɗan abokin aikin sarki na Constantius Maximian, wanda ya kwace taken sarki a ranar 28 ga Oktoba, 306. Amma yayin da Constantine ya yi ikirarin cewa Galustaerius, mai mulkin lardunan Gabas da babban sarki a cikin Daular, Maxentius ya yi amfani da shi a matsayin babban magajin sarki Maxentius.
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