CHICAGO — The origins of the board game Diplomacy can be traced to an old geography book that Allan B. Calhamer discovered while rummaging around with a friend in the attic of his boyhood home in suburban Chicago.

Calhamer was fascinated by the exotic countries and old boundaries laid out in the book, places like the Austro-Hungarian Empire and the Ottoman Empire.

The final inspiration came at Harvard, when Calhamer read Sidney Bradshaw Fay’s “The Origins of the World War” during Fay’s class on 19th century Europe.

“That brought everything together,” Calhamer told Chicago magazine in 2009. “I thought, ‘What a board game that would make!”‘

After being rejected by several game companies, Calhamer published 500 copies of Diplomacy in 1959.

The game came to develop a devoted following around the world.

Calhamer, 81, died Feb. 25 at a hospital in Chicago, his family said.

Since Diplomacy’s inception, hundreds of thousands of copies have been sold, with games also being played on the Internet.

President John F. Kennedy reportedly played it in the White House, and Henry Kissinger was a fan as well, according to newspaper accounts.

Games magazine named it to its Hall of Fame alongside classics such as Monopoly, Scrabble, Clue, Yahtzee and Sorry!

Described as a thinking man’s version of the popular game Risk, Diplomacy is a seven-player game based on the balance of power in pre-World War I Europe. Players are free to bluff and backstab one another to attain world domination.