Eventually the palace was converted and extended into a basilica to serve as residence of Pope St. Silvester I who consecrated it in the year 324 A.D.. From then on and until today, it serves as the seat – the cathedra – of popes as bishops of Rome. Unknown to many, the Basilica of St. John in Lateran was rededicated twice which led to the church being dedicated to the two St. Johns.
Ang orihinal na pagtatalaga ay isinagawa nga po ni Papa San Silvestre I noong taong 324 A.D. nang ikonsagra niya ang Basilikang ito sa Kamahal-mahalang Banal na Manliligtas. Ang unang muling-pagtatalaga ay naganap po noong ika-10 siglo nang italaga ni Papa Sergio III ang Basilika kay San Juan Bautista, samantalang ang ikalawang muling-pagtatalaga naman po ay pinangunahan ni Papa Lucius II nang italaga niya ang Basilika kay San Juan Evangelista noong ika-12 siglo.