John Emerich Edward Dalberg (Lord Acton)

John Emerich Edward Dalberg-Acton, 1st Baron Acton (1834–1902), known as Lord Acton, was an Anglo-German Catholic historian, liberal political thinker, and British peer. Educated in Europe, he became a leading advocate of individual liberty and constitutional government. Acton served as a Member of Parliament and later was appointed Regius Professor of Modern History at the University of Cambridge. He is best remembered for his warning about political authority—“Power tends to corrupt, and absolute power corrupts absolutely”—expressed in an 1887 letter. Acton also helped edit major historical projects and corresponded widely with scholars and statesmen.