Painted between 1503 and 1517, Da Vinci’s alluring portrait has been dogged by two questions since the day it was made: Who’s the subject and why is she smiling? A number of theories for the former have been proffered over the years: That she’s the wife of the Florentine merchant Francesco di Bartolomeo del Giocondo (ergo, the work’s alternative title, La Gioconda); that she's Leonardo’s mother, Caterina, conjured from Leonardo's boyhood memories of her; and finally, that it's a self-portrait in drag. As for that famous smile, its enigmatic quality has driven people crazy for centuries. Whatever the reason, Mona Lisa’s look of preternatural calm comports with the idealized landscape behind her, which dissolves into the distance through Leonardo’s use of atmospheric perspective.
Painting is an ancient medium and even with the introduction of photography, film and digital technology, it still has remained a persistent mode of expression. So many paintings have been limned over dozens of millennia that only a relatively small percentage of them could be construed as "timeless classics" that have become familiar to the public—and not coincidentally produced by some of the most famous artists of all time.
It leaves open the question of what mix of talent, genius and circumstance leads to the creation of a masterpiece. Perhaps the simplest answer is that you know one when you see one, whatever part of the world it's being held in. We, of course, have our opinion of what makes the grade, and we present them here, in our list of the best paintings of all time. Argue amongst yourselves.