John Boyle O’Reilly (1844–1890) is one of Ireland’s most remarkable and least known historical figures. An undercover Fenian while ostensibly a proud member of the British army, he was convicted of treason in 1866 and was transported to Australia. After a daring escape on an American whaler, he settled in Boston and worked at the Boston Pilot where he became editor and joint owner. But what really made O’Reilly’s name were his journalism and newspaper campaigns. This is the first complete study of O’Reilly’s short, extraordinary life.