Medusa (Leonardo)

For this purpose, then, Leonardo carried to a room of his own into which no one entered save himself alone, lizards great and small, crickets, serpents, butterflies, grasshoppers, bats, and other strange kinds of suchlike animals (some of these animals he dissected), out of the number of which, variously put together, he formed a great ugly creature, most horrible and terrifying, which emitted a poisonous breath and turned the air to flame; and he made it coming out of a dark and jagged rock, belching forth venom from its open throat, fire from its eyes, and smoke from its nostrils, in so strange a fashion that it appeared altogether a monstrous and horrible thing; and so long did he labour over making it, that the stench of the dead animals in that room was past bearing, but Leonardo did not notice it, so great was the love that he bore towards art.

Ser Piero, at the first glance, taken by surprise, gave a sudden start, not thinking that that was the buckler, nor merely painted the form that he saw upon it, and, falling back a step, Leonardo checked him, saying, "This work serves the end for which it was made; take it, then, and carry it away, since this is the effect that it was meant to produce."

This thing appeared to Ser Piero nothing short of a miracle, and he praised very greatly the ingenious idea of Leonardo; and then, having privately bought from a peddler another buckler, painted with a heart transfixed by an arrow, he presented it to the countryman, who remained obliged to him for as long as he lived.

Afterwards, Ser Piero sold the buckler of Leonardo secretly to some merchants in Florence, for a hundred ducats; and in a short time it came into the hands of the Duke of Milan, having been sold to him by the said merchants for three hundred ducats.Although art historians have doubted the veracity of this anecdote, Leonardo's shield (long since lost) has been said to inspire several early 17th-century painters who may have seen it in the collection of Ferdinand I de Medici.

Its full-page engravings, first produced in Florence in 1828, spread across Europe, making the painting one of the most popular in Leonardo's corpus of works.