Previously in our animated historical documentary series, we have covered events of the Crisis of the Third Century of the Roman empire and the creation of the Tetrarchy system by Diocletian. But that wasn't the end of the internal strife and civil wars between the Roman emperors. The battle of the Milvian Bridge of 312 AD was crucial, as it allowed Constantine the Great to take over part of the Empire and make Christianity the official religion of the realm.