Norman's paternal grandparents were Captain Martin Edward Haworth later Haworth-Leslie (d. 1886) and Mary Elizabeth Leslie, 18th Countess of Rothes.

In 1911 he was appointed lieutenant-colonel commanding the Highland Cyclist Battalion of the Territorial Force, which was badged to the Black Watch.

[3] He fought in the First World War and Leslie House, the ancestral family seat, became a hospital for the injured.

His wife, Noëlle, Countess of Rothes, worked ceaselessly during the war, both at Leslie House and in London at the Coulter Hospital, serving as a Red Cross nurse.

[5] They had two children: He died on 29 March 1927, aged 49, at their townhouse in Chelsea, London, and he was succeeded in the earldom by his eldest son, Malcolm.