Name this first Christian Roman emperor, in whose honor the city of Byzantium was  temporarily renamed.
The navy of this man's rival was decimated when this man's son defeated Abantus at the Battle of   Hellespont, and this emperor finally beat his rival at the Battle of Chrysopolis [kry-SAH-puh-liss].  This emperor put down Maximian's revolt after that man proclaimed this ruler was dead. He   supposedly saw a cross in the sky before defeating a force twice that of his at the Battle of Milvian  Bridge. This enemy of Licinius joined with him to support religious tolerance by issuing the Edict  of Milan. Name this first Christian Roman emperor, in whose honor the city of Byzantium was  temporarily renamed.
The navy of this man's rival was decimated when this man's son defeated Abantus at the Battle of   Hellespont, and this emperor finally beat his rival at the Battle of Chrysopolis [kry-SAH-puh-liss].  
Constantine I [or Constantine the Great; prompt on Constantine]