
The title of Madonna della Neve (Our Lady of Snow) has its origins in the 4th century AD, under Pope Liberius (352-366). In many parts of Italy, in honor of the Madonna della Neve, baby girl names as Biancamaria, or Maria Nives can be given.
The tradition is based on a legend told by friar Bartolomeo da Trento in the first half of the 13th century in Liber epilogorum in gesta sanctorum:
For a long time the elderly couple, who had no children, had wanted to use their wealth in a work that would honor the Mother of God, and to that end, they had prayed fervently that She would show them how to fulfill their desire.
The Virgin, moved by their religiosity, appeared to them in a dream, saying that in the place where the next morning they would find snow fallen miraculously overnight, they would have to build a church dedicated to Her name at their own expense.
Excited by the dream and the miraculous snowfall, the next morning Giovanni went to Pope Liberius, to tell him what happened: the pontiff had, during the night, dreamed the same! Liberius, followed by the patrician Giovanni and a large procession of people and prelates, went to the Esquiline hill, and on the still intact snow marked the limits of the new church, which was built at the expense of the patrician and his wife.
"On the morning of the 5th of August 352 the inhabitants of the Esquiline Hill had a strange surprise: during the night snow had fallen and a soft blanket covered part of the soil. With such a prodigy the Virgin Mary had indicated to a patrician, named Giovanni and his wife, that she wished a temple to be erected in that place in her honor.
The early church was demolished in the 5th century, under Pope Sixtus III (432-440) to be rebuilt more sumptuous, with the name of Basilica of Santa Maria Maggiore, in remembrance of the Council of Ephesus of 431 AD. Actually, the basilica was named "ad Nives" not before the 10th century, and there is no trace of the legend of the snow before that time.
In the 12th century the Feast Dedicationis Sanctae Mariae ad Nives was established and even today in the basilica on August 5, during the celebration of the Mass, white flower petals descend over the altar.

The Basilica of Santa Maria Maggiore is called "ad Nives" in a bull of Pope Nicholas IV in 1288, and to that year date the mosaics by Filippo Rusuti [a detail below], depicting the story of the miracle, still visible today in the 18th-century loggia that covers the original facade.
Since 1568 the official name of the liturgical feast of Our Lady of the Snows was amended in the phrase "Dedication of St. Mary Major" with celebration always on August 5, and the miracle of the snow in August is no longer mentioned, since for the Church it was legendary and never proven.
The painting below is named the "Founding of the Church of Santa Maria Maggiore in Rome" and is preserved in the Museo di Capodimonte, Naples; better known as "The Miracle of the Snow", it was painted by Tommaso di Cristoforo Fini, aka Masolino da Panicale, on orders of Pope Martin V Colonna for the church of Santa Maria Maggiore in Rome around 1428.