Listening to NPR today, they mentioned that a long lost mural of Leonardo da Vinci (500 years lost) The Battle of Anghiari has possibly been located. With clues that include a passage in a diary, and the phrase "cerca trova" the story unfolds like something out of a Dan Brown novel. "Cerca trova," which, translates roughly to "search and you will find," was painted on a fresco in the Palazzo Vecchio by Giorgio Vasari. It is believed that Vasari painted over da Vinci's mural because after he completed it (at the suggestion of Niccolo Machiavelli...yes, that Machiavelli), that the ruling family was displeased with the image because it depicted the folly, not the glory of war.
But there's more to the story: originally, the mural was to be coupled with another scene of war by an artist half da Vinci's age, Michelangelo. But this artistic battle of an era was never to happen, Michelangelo was lured to Rome by the pope, and da Vinci left his mural unfinished to go work for the king of France.
There is certainly enough extant da Vinci information for study. However, the more interesting facet of this story is the idea that da Vinci was painting an anti-war message for one of the most powerful families in Italy. It might force a re-imagining/thinking of political art...or at least a little revision?
*the pictured image is one of da Vinci's preparatory drawings for the mural.