March 17, 2008—Leonardo da Vinci may have helped illustrate a Renaissance treatise on chess—a page of which is pictured above—that was found in the library of an aristocratic family in Gorizia, northern Italy, researchers say.

The manuscript was penned around 1500 by Luca Pacioli, a mathematician and friend of Leonardo.

The treatise, "De Ludo Schaccorum"—Latin for "Of the Game of Chess"—includes more than a hundred chess problems that challenge the player to reach checkmate in a certain number of moves.

The sole copy of the treatise was found in 2006 among 22,000 volumes collected by the Coronini family in their palace in Gorizia, on Italy's border with Slovenia.

"It was like a Holy Grail of chess," said Serenella Ferrari Benedetti, cultural coordinator of the foundation that manages the Coronini estate. "We knew it existed but nobody had ever seen it."

After a year of research, Milan-based architect and sculptor Franco Rocco concluded that Pacioli enlisted Leonardo's help to draw the pieces.

Rocco told the Associated Press the futuristic style of the chess pieces is in sharp contrast with the way other pieces were represented at the time.

Every piece also was proportionally related to each of its parts and to the other pieces, a trademark of Leonardo's art, he said. In addition, some pieces directly recall other works by Leonardo, including a queen similar to a fountain drawn in one of the artist's manuscripts.

Not all the pieces display the same quality and some were drawn with a right hand and others with a left, Rocco said. This indicates that Leonardo, who was left-handed, may have only drawn a few pieces to provide examples, or that he simply suggested the designs to Pacioli, Rocco said.