 Constantine sent Galerius an official notice of Constantius 's death and his own acclamation . Along with the notice , he included a portrait of himself in the robes of an Augustus . The portrait was wreathed in bay . He requested recognition as heir to his father 's throne , and passed off responsibility for his unlawful ascension on his army , claiming they had " forced it upon him " . Galerius was put into a fury by the message ; he almost set the portrait on fire . His advisers calmed him , and argued that outright denial of Constantine 's claims would mean certain war . Galerius was compelled to compromise : he granted Constantine the title " Caesar " rather than " Augustus " ( the latter office went to Severus instead ) . Wishing to make it clear that he alone gave Constantine legitimacy , Galerius personally sent Constantine the emperor 's traditional purple robes . Constantine accepted the decision , knowing that it would remove doubts as to his legitimacy . 
