Leda and the Swan (copy)
It's Leonardo da Vinci; is there anything more that needs to be said? Of all artists, most deservedly or not, he is best known. Even on the lips of someone devoid of any tangible understanding of art, da Vinci can slip out, just as Einstein can out of the lips of someone completely ignorant of science. And there certainly is a strong emotional greatness in his art.
Interestingly, one of da Vinci's most famous paintings, Leda and the Swan, is actually preserved as a replica made by Cesare da Sesto. What happened to the original? As many great artifacts of our long-lived civilizations, it was lost, only recovered in the semblance of a copy; and for many grand works, we don't even have the much.
1480 - 1482
Head of a Man Shouting
The Battle of Anghiari