Harold was born in Marylebone in London, the second son of Alfred Withall Aston and Frances Amy Aston (nee Hennell) of 41 Bryanston Square, London and was baptised at St, Mary’s Church, Marylebone on 10 November 1884.

Alfred was a member of the Stock Exchange and at the time of the 1901 census, was living at Woodcote Grove, Epsom. According to John Toland, in his "Letter to Eudoxa," published in 1726, “this mansion is the original Mount Diston, so called from Josiah Diston, an early Governor of the Bank of England, who built it in the reign of Charles II., circa 1680. Its present occupant, Mr. A.W. Aston, has much altered the house. In the hall still hangs a portrait of Charles II, by Lely, where it was placed about 1680, and there exists also in the hall the fireplace where, it is recorded, Charles II cooked food. The walls are of brick and are 5ft.6in. thick”.

Harold went to Eton in September 1897, having been preceded by his father, and his brother Norman who died there in April 1900. Harold was in Mr J P Carter’s House and Mr A C G Heygate’s House.

Harold matriculated in 1904 and came up to Christ Church. He was elected as a Freeman of the City of London as a member of the Worshipful Company of Skinners on 19 April 1906.  

After Oxford, he was commissioned as a 2nd Lieutenant in the Surrey Yeomanry (Queen Mary’s Regiment) on 28 July 1906 but later resigned his commission.

On 8 November 1910, Harold married Evelyn Langham Reed at St. Thomas’s Church, Portman Square. In 1911, they first lived at 11 The Red House, Bell Street, Sawbridgeworth, Hertfordshire and later at Orchard House, Iwerne Minister in Dorset.

Following the outbreak of war, Harold was commissioned as a 2nd Lieutenant in his former regiment on 6 August 1914 and was appointed to the command of 3 Troop, B Squadron 1/1st Regiment. He embarked for France with his regiment on board the SS “Kingstonian” on 17 January 1915, landing at Le Havre the following day. He was promoted to Captain on 14 June 1918, seeing service in both France and the Balkans. He transferred to the Queen’s Own Dorset Yeomanry with the rank of Captain on 2 September 1920 and transferred to the 4th Battalion Dorset Regiment on 14 April 1921 before resigning his commission on 6 July 1921. He was re-appointed to the 94th (Somerset & Dorset Yeomanry) Field Brigade, Royal Field Artillery on 31 March 1922 with the same rank and was promoted to Major on 30 September 1922. He was awarded the Territorial Decoration on 13 January 1928. Having reached the required age, he retired from the service with the rank of Major on 29 September 1936.

His name appears in Kelly’s Directory for 1935 as Major H.W. Aston T.D., R.A. Commanding Officer of the Shaftesbury Territorial Army, living at Preston House, Iwerne Minster.

The Christ Church records show that a letter received on April 2nd 1936 confirmed his address and rank of Lt. Col. Dorset (Q.O.) Yeomanry.

Following the outbreak of war, he was granted a commission as a Pilot Officer in the Royal Air Force Volunteer Reserve on 2 July 1940 for the duration of hostilities.

He died at the Military Hospital, Douglas, Isle of Man and is buried in St Mary’s, Iwerne Minster Churchyard.

He is commemorated on the war memorial at Eton College and on the memorials at Lloyd’s of London at Iwerne Minster.

His estate amounted to £14,044-7-2 and probate was granted to his widow and a solicitor.