Santa Maria Maggiore,  one of the holiest basilicas in Rome, is known as a center of the “cult of the virgin,” or the primarily Roman Catholic focus on the holiness of the Virgin Mary, and the fervently focused reverence some Catholics develop towards her.  Santa Maria Maggiore was built shortly after the Council at EphesusFloorplan (431 C.E.).  This meeting of the Church was highly controversial because it centered around the question of the divinity of Christ.  For hundreds of years, different sects of Christianity (at this time synonymous with what we now call “Catholicism”) had been cultivating their own opinions on just how divine, and conversely how human, Jesus Christ was.  The congregated leaders at Ephesus decided that Christ had been half each, as it were; that is, equally god and man.  Hence, this made Mary the mother of a divine being - or, as the Church officials began putting it, the Mother of God. 
   Thus a feverish trend toward honoring the Virgin was born.  Santa Maria Maggiore was the product of a dream had by Pope Liberius, the leader of the Church at the time.  Liberius dreamt that Mary appeared to him and instructed him to build her a church on a specific spot in Rome.  She told him that he would know the place by a miraculous snowfall which she would create (this was in the middle of August, by the way).  Sure enough, the next day, the Pope was shown the way, and commanded the construction of Santa Maria Maggiore, or “Saint Mary Major.” 
   The basilica is particularly famous for its beautiful mosaics.  They date from the early 5th century, and are primarily depictions of Mary, Jesus, and their genealogy.  Some of the mosaics are missing, and were replaced in the 16th century.
   The mosaics can be divided into three categories for consideration: the framed panels in the nave, of which 25 survive; the mosaics in the triumphal arch; and the main mosaic in the apse.  This site focuses on the nave and arch mosaics.
   The mosaics in the nave depict the Hebrew  (“Old”) Testament.  The mosaics in the triumphal arch depict the New Testament.

     There are interesting contrasts between the two assemblies of pictures.  The nave (Hebrew Testament) lacks the strong gold backgrounds so prevalent in the triumphal arch (New Testament).  The gold in the arch makes the pictures there stand out and look more important; they draw the focus aisle of the viewer to the new, “better” (in the eyes of the Church in the 5th century) books of the Bible.  The nave is more purely classical in style, so that the arch seems to progress from it not only in chronology and righteousness, but also in technique.  There were clearly politics (or at the very least, forceful dogma) at play in the creation of these mosaics.