Union Jack is the name of three fictional characters that appear in comic books published by Marvel Comics.
Brian Falsworth is the son of James Montgomery Falsworth, born like his father in Falsworth Manor in a village north of London. Brian and his friend and lover Roger, are both initially sympathetic toward Germany and supportive of peace between it and the United Kingdom. Toward the end of the 1930s, the pair go into Germany, but quickly discover the evil nature of the Nazi regime. Brian is thrown in prison, and Roger is given to German scientists.
Joseph Chapman's incarnation as the current Union Jack is unique in that he is not a member of the Falsworth line or part of any British aristocratic family. Rather, Joey Chapman, born in Manchester, England, is the working class son of a shipbuilder.