 In addition to his full @-@ brother Alexander , Mosley has five older half @-@ siblings . On his father 's side they are Vivien Mosley ( 1921 – 2002 ) , novelist Nicholas Mosley , 3rd Baron <unk> ( born 1923 ) , and Michael Mosley ( 1932 – 2014 ) . On his mother 's side they are merchant banker Jonathan Guinness , 3rd Baron <unk> ( born 1930 ) , and Irish <unk> Desmond Guinness ( born 1931 ) . He is a third cousin of the late Winston Churchill , the grandson of the former British prime minister . 
