active 1288-1322 de Cessolis Jacobus

Active between 1288 and 1322, this Italian writer and Dominican friar is best remembered for a moral treatise usually known as The Book of Chess. Rather than teaching strategy, the work uses the chessboard and its pieces to explain the duties of different ranks in society, from rulers and nobles to tradespeople and common citizens.

The book grew out of sermons and became widely copied and translated, which helped it travel far beyond its original setting in northern Italy. Its influence lasted for centuries, and it is closely tied to William Caxton's The Game and Playe of the Chesse, one of the earliest books printed in English.

Very little seems to be known with certainty about his personal life beyond his religious order, his Italian background, and the remarkable success of his writing. Even so, his work remains a fascinating window into how medieval readers connected games, ethics, and everyday life.