During the upheavals of 2007–09, the chairman of the Federal Reserve had the name of one Victorian icon on the tip of his tongue: Walter Bagehot. Banker, man of letters, and inventor of the Treasury bill, Bagehot prescribed the doctrines that—decades later—inspired the radical responses to the world’s worst financial crises. Persuasive and precocious, he was also the esteemed editor of the Economist. He offered astute commentary on the financial issues of his day, held sway in political circles, made as many high-profile friends as enemies, and won the admiration of Matthew Arnold and Woodrow Wilson. Drawing on a wealth of historical documents, correspondence, and publications, James Grant paints a vivid portrait of the banker and his world.