The second child of William and Alice Arm (née Martin), Henry was born on 9 April 1900 in Alverstoke, Gosport, Hampshire, with his elder brother Reginald, born circa 1898, and joined in 1902 by his sister Winifred. Tragedy struck the family early with the death of his mother soon after the birth of Winifred. The family unity was preserved when Alice’s mother moved into the family home in 38, Pelham Road, Alverstoke.

Henry joined the Royal Navy on 19 January 1916 when he boarded the 3 mast, 3 deck training ship HMS IMPREGNABLE (ex HMS HOWE) at Devonport for the approximate 16 week part one training. Transferring to the stone frigate HMS GANGES at Harwich, Essex, on 13 May for branch training, he was selected for the communication branch as a Boy Telegraphist on 3 July before a draft to HMS VICTORY on 20 October for a further 3 weeks specialist training. On 9 November 1916 he moved across Portsmouth Harbour to HMS DOLPHIN for a 5 week submarine acquaintance course. He left DOLPHIN on 21 December to join HMS LUCIA for HMS E49 in the new harbour of Teesport near the mouth of the River Tees.

E49 was lost with all hands off the Shetland Islands on 12 March 1917. Henry was 16 years and 11 months old, his Service Certificate states “Lost On Duty”. He is commemorated on the Portsmouth Naval Memorial on Panel 25.