As Constantine the Great prepared to engage in battle against his rival Maxentius, a pivotal moment occurred that would alter the course of history. Reports indicate that Constantine experienced a profound vision in the skies, where he perceived a luminous cross appearing above the sun. Accompanying this surreal sight was the inscription 'In hoc signo vinces,' which translates to 'In this sign, you will conquer.' This vision is said to have inspired him greatly as he led an army of approximately 40,000 troops towards the Battle of Milvian Bridge, near Rome. Convinced by this miraculous event, Constantine ordered his soldiers to adorn their shields with the Christian symbol, leading to a unified and determined force ready to fight for their belief.

The result of this battle would be transformative. On October 28, after an intense confrontation, Constantine's forces defeated Maxentius, significantly altering the power dynamics within the Roman Empire in favor of the former. This victory initiated the start of Constantine's reign as the sole ruler of the Western Roman Empire and marked the beginning of the Empire's acceptance of Christianity. Following this event, Constantine issued the Edict of Milan in 313, legalizing Christianity and allowing it to flourish throughout the empire.

The aftermath of the vision and subsequent battle led to significant developments, notably the establishment of the Council of Nicaea and the inception of state-supported Christianity. Constantine's legacy as a Christian emperor set the precedent for the later adoption of the Christian faith as a dominant religion within Europe. Thus, his vision not only played a crucial role in his military success but also shaped the theological and political landscape of Western civilization for centuries to follow.