[3] Salisbury sought to imply that Parnell encouraged the Phoenix Park murders in 1882, and that he was linked to the dynamite outrages in England which culminated in a bomb in the House of Commons in 1887, the year of Queen Victoria's Golden Jubilee.

What was kept secret was that in 1885 Lionel Carden, then acting chargé d'affaires at HM Legation in Mexico, interviewed General Millen and with government approval recruited him as a spy, and became his paymaster.

Through intermediaries General Millen was directed by Lord Salisbury to ensure that the dynamite explosions continued, thereby creating public outrage against Irish nationalists and Parnell.

General Millen met Lionel Carden again in 1888 with an offer, for a very large sum of money, to appear as a witness at the hearing mentioned above, which was about to take place.

[6][7] On 18–20 April 1914 Carden returned on the armoured cruiser HMS Berwick (sailing via Galveston to Veracruz) to continue to serve briefly as British Minister to Mexico, during the last three months of the Victoriano Huerta regime.