John Emerich Edward Dalberg-Acton (1834 - 1902)

Known as Sir John Dalberg-Acton, 8th Bt from 1837 to 1869 and usually referred to simply as Lord Acton—was an English Catholic historian, politician, and writer. He is famous for his remark, "Power tends to corrupt, and absolute power corrupts absolutely. Great men are almost always bad men."