John Mitchel (1815-75) was born at Camnish, near Dungiven, Co. Derry, the son of a Presbyterian minister. After qualifying as a solicitor, he became a leading contributor to the Nation newspaper and the most militant of the Young Irelanders. Sentenced to 14 years' transportation for attempting to incite rebellion in Ireland in 1848, in captivity he wrote his famous Jail Journal, which starkly expressed his hatred of the British empire and had an immense influence on later nationalists. Escaping to America after five years, he became a strong supporter of slavery and the Confederate States, and two of his sons died fighting for the South.The harshness of his views, especially his violent hatred of Britain and support for slavery, does much to explain Mitchel's neglect in recent decades. He was, however, one of the most powerful polemical journalists of the nineteenth century and a central figure in the revival of militant Irish nationalism. His portrayal of the famine as deliberate genocide became central to nationalist orthodoxy, and his hatred of British rule and contempt for parliamentary politics did much to inspire Fenianism.This new biography attempts to discover the origins of Mitchel's views, to examine their influence, and to place his anglophobia in a more general critique of the age in which he lived.