Pontificate
His elections marked the end of a period sede vacante lasting from the death of Pope Eusebius on 17 August 310 or, according to others, 309, soon after the Emperor Maxentius had exiled Eusebius to Sicily.
During his pontificate, in October 312, Constantine defeated Maxentius and assumed control over Rome. Constantine presented the pope with the Lateran Palace which became the papal residence and seat of Christian governance. Early in 313, Constantine and fellow Emperor Licinius reached an agreement at Milan that they would grant freedom of religion to the Christians and other religions and restore church property.
Read more about this topic: Pope Miltiades