When the emperor Constantine had received health and salvation through the sacrament of Baptism, he promulgated an edict making it legal for the first time for Christians throughout the whole world to build churches. He encouraged this holy work by example as well as by decree.

In his Lateran Palace, he dedicated a Church to the Savior, and adjacent to it built a basilica named for Saint John the Baptist. This basilica is on the very spot where Constantine had been baptized by Saint Sylvester and cleansed from the leprosy of paganism.

This, the same Pontiff consecrated on the 9^th of November. The anniversary of this consecration we keep today, for the first time in history, a church was consecrated publicly in Rome.

On that day also, in the sight of the Roman people there appeared upon the wall of the basilica as though painted, an image of the Savior.

Roman Breviary - Benziger Brothers, 1964

@Evangelizo