This video above explains the architectural structure and design. And closes with a view o the 1295 mosaic of Saint Anthony of Padua, whom we invoke each night during the Supplica.
Then, there is this 2 Part Documentary.
This video begins with a recount of the vision of 358 A. D., when the Patrician John had a dream in which Our Lady showed the place on the Esquiline Hill where She wanted a Church built in Her honor. Indicating the place with a miraculous snowfall on the night of August 4-5, 358. The Mosaics of the Basilica retell the story.
Then, it discusses the history of the Esquiline Hill before 358 A.D., to understand the ancient history of the place. There was a Roman Patrician Villa from the 2nd to 3rd Century. There are roof tiles of that place from the reigns of the Emperor Nero onwards. And some marked as having being made for the House of the Mother of Christ.
Santa Maria Maggiore is the only true ancient Roman Basilica which has remained in the City of Rome. The present structure was build by Pope Sixtus in 430-431, at the time of the dogmatic definition of the Council of Ephesus which declared Our Lady, Mother of Christ. Thus, Santa Maria Maggiore is the first Church in the entire Christian world built to the honor and glory of the Holy Virgen. That it has remained intact shows that She cares for this place with a special love of remembrance of that gift to Her.
This video discusses the art added by Pope Nicholas IV, the first Franciscan Pope, c. 1295. this video there is a brief view of Saint Francis of Assisi whom we invoke each night in the Supplica, to the far left of the central principal mosaic in the Dome above the High Altar.
At about 9 minute mark, the chapel of Our Lady, Salus Populi Romani, built by Pope Paul V, is shown, the Icon of which dates from 1050 – 1150 A. D…
The gold leafing on the wooden ceiling of the central Nave was an offering of Christopher Columbus’ Voyages of Discovery of the New World.