Short answers, pulled from the story.
Constantine the Great was born on the 27th of February 272 in the city of Naissus, now known as Niš in Serbia. He was the son of Flavius Constantius and Helena, a woman of low birth who likely spoke Greek.
Constantine the Great executed a daring escape by fleeing the palace at night and riding from post-house to post-house at high speed. He hamstringed every horse in his wake to prevent pursuit and successfully reached his father in Gaul before Galerius could catch him.
On the 28th of October 312, Constantine the Great defeated his rival Maxentius at the Battle of the Milvian Bridge. His forces broke Maxentius's lines and pushed the enemy into the Tiber River, where Maxentius drowned and Constantine entered Rome on the 29th of October 312.
Constantine the Great officially dedicated Constantinopolis on the 11th of May 330 as a new capital to replace the aging city of Rome. The city was founded in 324 and served as the seat of the Eastern Roman Empire for over a millennium while shifting the center of power from the West to the East.
Constantine the Great was baptized by Eusebius of Nicomedia on his deathbed on the 22nd of May 337. He implemented reforms such as the Edict of Milan in 313, convoked the First Council of Nicaea in 325, and issued laws making Sunday a day of rest for all citizens.