 Blunt was born on 24 September 1879 in Saint-Malo, France, where he was brought up before his mother returned the family to England in 1887.He was younger son in second marriage of Captain F. T. Blunt (died 1881) of the British colonial service, ultimately Chief Civil Commissioner for the Seychelles.He was privately educated by his widowed mother, and attended Church Hill preparatory school at Crondall near Farnham, Hampshire, before entering Marlborough College in 1893.