The fragments of antiquity which now exist in our museums are by and large Roman copies of the lost Greek originals. In 1500 even they were still buried waiting to be excavated. The existing Roman frescoes survived because the disastrous eruption of the volcano in Pompeii sealed them under a ton of lava.
So Venus had not been honored with a portrait for a thousand years. Botticelli painted several works dedicated of the goddess. Most important after La Primavera is the Birth or Rebirth of Venus. The nude female body - forbidden territory for a painter - is shown by Botticelli with his trademark elongation. Venus is reborn in Italy bringing new hopes to mankind. The stunning results send shockwaves throughout aristocratic Europe.
Mythology soon became a justification for Renaissance and Post-Renaissance artists to paint with a new freedom and boldness denied them by Christianity. The explicit moral commandments of Christianity, above all, humility meant that important human emotions and attitudes could hardly be glorified in properly Christian terms. Since Europe had by no means renounced the values of pagan nobility - honor, pride, vengeance, self-assertion, magnanimity - these values found a haven in the representation of classical antiquity.
But before Botticelli could develop these themes, the fanatical Christian monk Savanarola rose to power in Florence with his fire and brimstone sermons. In his legendary bonfires of the vanities he urged the citizens to burn all pagan works. His deadly campaign to stamp out luxury and vice almost destroyed the greatest city of art the Europe has known. Luckily for art, the monk proved too fanatical even for his own followers, and much too much for the Pope, who ordered him excommunicated and then burnt in the town square.
Poor Botticelli never recovered his nerve. He spent his last years painting rather unpleasant allegories like The Calumny of Apples, or Christian apocalyptic pictures, i.e. the Mystical Nativity and the Mystical Crucifixion.

James Phelan, Forbidden Visions: Mythology in Art, in the industrious, the so-deeply-embedded-as-to-be-synonymous-with-art-online, the standard by which all others are to be judged, artcyclopedia May, 2000

bergerfoundation has an impressive wealth of images and organization but the images themselves are poorly reproduced. abc gallery has a wealth of images, yet also...
National Gallery, London, has good reproduction values but the image is small
this Italian site, mezzo mondo, is like that too, and the pioneering Web Gallery of Art still has 90's lo-fi, but they have this Maynard Keenanish portrait of Mr. Bonfire
here's a photo of a statue of Savonarola in his hoodie. and the same statue. and to cleanse the palate after all that blackened book, a different statue.

{where am I at with all that? none of your business.}