Final answer:
Before his decisive Battle of Milvian Bridge, Constantine had a significant religious vision of a cross in the sky, which he interpreted as a divine sign of promised victory. This experience influenced him to promote Christianity within the Roman Empire through the Edict of Milan.
Step-by-step explanation:
The experience Constantine had before his important battle, specifically the Battle of Milvian Bridge in 312, was that of a profound religious vision. According to historical sources,
Constantine
saw a
cross in the sky
and attributed it to the Christian God. He believed this vision was a divine sign promising him victory in the battle. It played a crucial role in his decision to promote Christianity, leading to the issuance of the
Edict of Milan
in 313, which declared Christianity a tolerated religion within the Roman Empire.
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