For 10 points, name this fourth century emperor who ended the persecution of Christians.
This emperor disbanded the Praetorian Guard and replaced them with the Palatini Comitenses. Before one decisive battle against Maxentius, this emperor saw a chi rho in the sky with the inscription "In this sign, you will conquer." After defeating his rival Licinius, this emperor made Byzantium his capital and renamed it after himself. This emperor convoked the (*) Council of Nicea and promulgated the Edict of Milan to increase religious toleration. For 10 points, name this fourth century emperor who ended the persecution of Christians.
This emperor disbanded the Praetorian Guard and replaced them with the Palatini Comitenses.
{Constantine} I [or {Constantine} the {Great}; or Flavius Valerius {Constantinus}; prompt on