Although his place of birth was Hendon, in the north of London, United Kingdom, he was raised on the Isle of Wight and was educated there, at Ryde School.

In March 1938, he applied to join the Royal Air Force (RAF) on a short service commission.

[1][2] His application was successful and he was granted his RAF commission, initially as an acting pilot officer on probation, with effect from 7 May 1938.

54 Squadron carried out patrols and the occasional interception mission but otherwise saw little action until May 1940, when the Germans invaded France and the Low Countries.

It then began to fly sorties over France as the British Expeditionary Force (BEF) retreated to Dunkirk.

It became fully engaged in the Battle of Britain the following month, regularly flying from Rochford and Manston in the southeast of England.

54 Squadron was back at Hornchurch by early August and resumed flying in the ongoing battle over Britain.

[6] On 13 August 1940, Gribble's award of a Distinguished Flying Cross (DFC) was announced; the citation, published in the London Gazette, read: Since the outbreak of war, this young officer has taken part in most of the offensive patrols carried out by his squadron, including operations over the Low Countries and Dunkirk, and intensive air fighting over the Channel.

Pilot Officer Gribble has led his section, and recently his flight, in a courageous and determined manner.

On one offensive patrol, having expended his ammunition, he did not hesitate to lead two other pilots of his section, under severe cross-fire, in an attack against a formation of six Dornier 17's.

He shot down two Bf 109s on 28 August; the first was in the morning, part of the fighter escort for a group of Do 17s that was targeting the RAF airfield at Rochford.

Despite the move north, it was still called upon for interception missions, and on 27 October, Gribble was credited with damaging a Junkers Ju 88 bomber.

Now equipped with the updated Spitfire Mk IIa, it regularly flew across the English Channel to the Low Countries, carrying out offensive sweeps and escorting bombers.

[5] On 4 June, and by this time a flight lieutenant, he was leading a section of Spitfires that were escorting bombers when they encountered a pair of Bf 109s.

Attempting to engage these, he in turn was intercepted by other Luftwaffe fighters and the engine of his Spitfire was apparently damaged.