In the first modern biography of Lord Mansfield (1705-1793), Norman Poser details the turbulent political life of eighteenth-century Britain's most powerful judge, serving as chief justice for an unprecedented thirty-two years. His legal decisions launched England on the path to abolishing slavery and the slave trade, modernized commercial law in ways that helped establish Britain as the world's leading industrial and trading nation, and his vigorous opposition to the American colonists stoked Revolutionary fires. Although his father and brother were Jacobite rebels loyal to the deposed King...