He invades Thrace with a Visgothic force and raids the countryside .
July 3 -- Battle of Adrianople : Emperor Constantine the Great defeats his rival Licinius near Adrianople , forcing him to retreat to Byzantium .
Emperor invades Thrace with a Visgothic force and raids the countryside .
July 3 -- Battle of Adrianople : Emperor Constantine the Great defeats his rival Licinius near Adrianople , forcing him to retreat to Byzantium .