Knowles Stock was born in Babinda, Queensland, Australia. He enlisted with 9 Bedfordshire and Herfordshire's GSC on 5 February 1944. Service records state that Knowles' trade before enlistment was an 'instrument maker'.

He then volunteered for service with The Parachute Regiment and passed his parachute jump qualification course at RAF Ringway on Course B164, 13 May to 2 June 1945. 211 men listed as reinforcements to Airborne Divisions plus a few members of 1st and 2nd SAS took part on this course. Knowles' instructor stated this about his performance "Satisfactory. Very keen good jumper".

Knowles was posted to Depot and held in a Reserve Para Bn, until he was posted to 224 Para Field Ambulance RAMC in June 1945. His rank at this time is recorded as Unpaid, Acting, Sgt. 

He was then posted as a member of this RAMC unit, to Palestine for peace keeping duties. He served here between 22 September 1945 and 15 January 1948.      

Knowles was discharged with an 'Exemplary' record 20 October 1948, With the rank of Sgt. 

In October 1948, Knowles, now living in Plaistow, joins 4th Para Field Ambulance (TA) as a reservist, at Bushfield Camp, RAMC, Winchester. He is issued a new service number. He attends the required annual 15 day camp each year, 1949, 1950 and 2 in 1951. Then in May 1952 Knowles leaves the Reserves, with the rank of Sgt. 

Biography based on service records shared by Richard Stock (son)