The Most Hon. Henry Vivien Pierpont Conyngham, 8th Marquess Conyngham (born 25 May 1951), styled as Viscount Slane until 1974 and as Earl of Mount Charles from 1974 until 2009 and predominantly known as Lord Mount Charles, is an Anglo-Irish nobleman who is best known for the rock concerts that he organises at his home Slane Castle, and for his column in the Irish Daily Mirror under the byline "Lord Henry".