[1][5] He was Parliamentary Private Secretary to Walter Runciman between 1911 and 1915 and then briefly held office under H. H. Asquith as Under-Secretary of State for the Home Department between February and May 1915.

[7] Apart from his political career Harmsworth was a director of Amalgamated Press and chairman of Associated Newspapers, founded by his brother Lord Northcliffe.

He published Pleasure and Problem in South Africa (1908), Immortals at First Hand (1933) and A Little Fishing Book (1942).

[1] Harmsworth purchased Dr Johnson's House and restored it into a museum open to the public.

[8] Lord Harmsworth married his cousin Emilie Alberta, daughter of William Hamilton Maffett, in 1897.