Henry was born on the 19 June 1901, the first child of George Hazelden and Emily (née Coleman) French in Hastings Sussex. At the time the family were in the middle of changing the surname from French to Hazelden-French, a carry over from a marriage in 1872 when Thomas Henry French married Esther Heselden. Brothers John Thomas (1905), Cyril William (1906) and many years later Edmund (1921) completed the family unit.

Henry joined the Royal Navy on 12 September 1917 when he entered HMS GANGES in Shotley, Suffolk, aged 16 years and 3 months as a Boy Second Class, for one year’s basic training. He was selected as Telegraphist and rated Boy Telegraphist on 20 February 1918. On completion of training he was drafted to HMS VICTORY 1 in Portsmouth on 5 September 1918 for 1 month before moving across Portsmouth Harbour to HMS DOLPHIN on 18 November for HMS L55. On 1 February 1919 L55 was transferred to the depot ship HMS LUCIA and moved to Tallinn, Estonia, for patrols in the Baltic Sea.

On 4 June 1919, L55 sank with the loss of all 42 crew members. Boy Telegraphist First Class Henry George Hazelden-French was one of those that perished. After the wreck of L55 was recovered in 1928, he was buried with the rest of the crew in the Haslar Royal Naval Cemetery in the L55 Grave.