St. John Lateran is the first great basilica where the entire Christian community of a city could gather. The Emperor Constantine built it at his own expense and donated it to the Bishop of Rome, along with the adjoining baptistery and episcopal palace. Two enormous columns from the ancient basilica are still visible at the top of the central nave, before the transept. Listen to Msgr. Andrea Lonardo, Director of the Catechetical Office and the Service for Catechumenate of the Diocese of Rome.