Just prior to fighting forces loyal to Maxentius Daia in the Battle of the Milvian Bridge on Oct 28th, 312 AD, it is reported that Constantine saw in the sky the image of the labarum, (above picture). The labarum was among several images placed used by the early, persecuted Christian church to designate Christian house churches and meeting places in an esoteric manner. The labarum consists of superimposing the Greek letters Chi, which resembles an "X" and the Greek letter Rho, which resembles a "P". These letters form the first the first two letters of the word "Christ".
Along with the claimed vision, reportedly Constantine heard the words (In Latin) "In hoc signo vinces" (in this sign, victory). Constantine ordered the symbol to be painted on shields, helmets and all manner of military hardware and banners and by the end of the subsequent battle, the weight of the retreating, thoroughly routed forces of Maxentius caused the pontoon bridge he had constructed over the river Tiber to collapse, killing many retreating Maxentian soldiers. Victory was decisively in favor of Constantine who, in 313 AD, would then issue the now famous Edict of Milan, effectively ending the persecution of the Christian church by Roman authorities. Although if one wished to be technical, it was actually under the emporer Theodocius that Rome officially became Christian in 380 AD.
Historians debate whether or not Constantine himself was truly a Christian, even when his acceptance of baptism on his deathbed is considered. However an article out today by Mark Tooley provides some interesting insights and hypotheses into the life of the roman emperor....
"Constantine is often derided as a brute who usurped the church to enhance his own rule over the empire. His critics note that that he governed and waged war bloodily like all such emperors, and that he purportedly executed his wife and son. The more extreme conspiracists, echoing the Da Vinci Code's fiction, accuse Constantine of imposing theological orthodoxy, even Christ's divinity, upon an obedient Council of Nicaea. Anabaptists typically fault him for turning previously pacifist Christians into willing soldiers for Rome and all subsequent empires. The neo-Anabaptists are most distressed by Christians who support today's American "empire."
In response, Presbyterian theologian Peter Leithart has penned a very important book, Defending Constantine: The Twilight of an Empire and the Dawn of Christendom. He not only competently restores Constantine's reputation but also thoughtfully and polemically rebuts the Anabaptists, specifically including John Howard Yoder. A senior fellow at new Saint Andrew College in wonderfully named Moscow, Idaho, Leithart argues that Constantine's conversion was sincere, that his legalization of Christianity was a tremendous relief to the persecuted church, that his Christian inspired legal reforms ameliorated some of Rome's pagan savagery, that he respected the church's autonomy, and that he desacralized the empire and began the end of all civic pagan burnt offerings once so universal. Leithart also persuasively disputes that the early church was decisively pacifist. Despite Anabaptist claims, especially by Yoder, there simply is not sufficient evidence to show the early church had ratified a teaching on military force. Leithart points to the usual New Testament examples of Jesus and His apostles not objecting to force by civil authorities. He also describes the pagan sacrifices once required within the Roman military, probably enhanced in reaction to Christianity's growth, and which prohibited service by Christians who otherwise did not object to legitimate force. Constantine's abolition of state-imposed pagan sacrifices removed this barrier for Christian military service."
I invite anyone who is an amatuer history buff like myself to examine the article in it's entirety and offer up their thoughts in the comment box.