 Although Constantine 's death follows the conclusion of the Persian campaign in Eusebius 's account , most other sources report his death as occurring in its middle . Emperor Julian ( a nephew of Constantine ) , writing in the mid @-@ 350s , observes that the Sassanians escaped punishment for their ill @-@ deeds , because Constantine died " in the middle of his preparations for war " . Similar accounts are given in the Origo Constantini , an anonymous document composed while Constantine was still living , and which has Constantine dying in Nicomedia ; the Historiae <unk> of Sextus Aurelius Victor , written in 361 , which has Constantine dying at an estate near Nicomedia called <unk> while marching against the Persians ; and the Breviarium of Eutropius , a handbook compiled in 369 for the Emperor Valens , which has Constantine dying in a nameless state villa in Nicomedia . From these and other accounts , some have concluded that Eusebius 's Vita was edited to defend Constantine 's reputation against what Eusebius saw as a less congenial version of the campaign . 
