When President Donald Trump sat down for an interview in March with New York Times reporters Maggie Haberman and Jonathan Swan for their new book, he showed them a document arguing he was more powerful than some of the most feared and treacherous leaders in history — including Attila the Hun, Genghis Khan, Napoleon, Stalin, Mao, and Hitler.

Trump had been asked by Haberman and Swan about the power he wielded as president in his second term and his place in history, which prompted him to tell the story of a two-page document he had received from “a historian” during an event honoring the hall of fame golfer, Gary Player. Trump proudly asked an aide to fetch a copy of the document, which argued that each of the other leaders, “however fearsome in his day, had no global reach. Their power was local. But (Trump’s) was not.”

Trump proudly showed them the letter, Haberman and Swan write, “reciting the names of some of history’s most powerful figures, explaining how each fell short of his own power as US president.”

These leaders “maintained power through fear,” Trump said, according to the book. “Who would ever do a thing like that? Right?”

But when Swan and Haberman tried to find the author, it turned out, he was not a historian, but actually Player’s longtime caddy and personal confidant. The caddy told Haberman and Swan that he “had first shared his assessment of Trump’s power with Player and later explained it directly to Trump over golf in Florida.”