Licinius escapes and gathers around 30,000 of his surviving troops at Nicomedia .
September 18 -- Battle of Chrysopolis : Constantine I definitively defeats Licinius at Chrysopolis , and becomes sole Emperor , thus ending the period of the Tetrarchy .
Licinius escapes and gathers around 30,000 of Constantine I 's surviving troops at Nicomedia .
September 18 -- Battle of Chrysopolis : Constantine I definitively defeats Licinius at Chrysopolis , and becomes sole Emperor , thus ending the period of the Tetrarchy .