S/Ldr H. Szczesny was born in Warsaw and went to college there. He became an army cadet before joining the Polish Air Force at Deblin.
He fought the Germans in Poland and was wounded. He escaped to Malta by ship the arrived at Eastchurch via France. 
Henryk joined No 74 Squadron in August, 1940, after converting to Spitfire's and learning English.
On 13th August, 1940 (Adler Tag - Eagle Day), after shooting down a Dornier 17, he was forced to land at West Malling airfield. Damage susatined in combat meant he was unable to lower the undercarriage to land, but his Spitfire (K9871) was repairable.

On 26th February 1941, Flying Officer Henryk reported for duty, along with Acting Squadron Leader Brzezina, to 317 Squadron, then stationed at Acklington.

On 19th April, Henryk was invested with the D.F.C. at 11.00 hours by A.V.M. Andrews., A.O.C. 13 Group.

On 29th June, he returned from time away from the squadron attached to operations (unknown).
On 10th July, Henryk shot down an Me109, a shared victory with Sgt. Brzeski.
On 14th July, between 17.35hrs and 18.45hrs, he and Sgt. Brzeski were on patrol when they sighted Ju 88 at sea level about to attack convoy convoy 10 miles south of Worms Head. They made a dive head attack, fronted and got in good bursts in and pursued it until it fell into sea. No damage was done to the convoy.

On 11th November 1941, Henryk, by then a Squadron Leader, was one of eleven members of 317 Squadron (then at Exeter) to receive the The "Krzyz Walecznych" by the President of Poland, and Henryk also received the "Virtute Military".

On 30th December, the squadron took off from Bolthead as part of a Wing with 306 squadron on patrol over the French Coast North of Brest, when they encountered nine German bombers and twenty Me109 fighters. The Wing attacked the enemy fighters in line astern. In the ensuing battle, Henryk fired a short burst at one Me 109 from 200 yards astern, whereupon it rolled and dived vertically into cloud. Although no claim was made, the engagement was under investigation. No cine camera was carried.

On 2nd February 1942, Henryk was assigned temporary duty to the Polish Inspectorate General. On 14th February, he returned to the squadron at Exeter having completed a course at Shrivenham.
On 24th February, the Air Minister, The Rt. Hon. Sir Archibald Sinclair, visited the Station by air. He was introduced to the Squadron Commander (Squadron Leader Szczesny) who conducted him on a tour of the flights where he interviewed the pilots.

On 1st March, Henryk was posted for a short time to HQ Fighter Command as Liaison Officer for H.Q. 10 Group.
On 7th March, Henryk handed over the Squadron to F/Lt Brzezinski, the new Squadron Commander, and on 9th March, was posted to H.Q. 10 Group for temporary duty.

His tally of kills was 8 confirmed, 3 shared 1 probable and 2 damaged.

Henryk Szczesny took up his posting to 74 Squadron with fellow countryman Flight Lieutenant Stanislaw Brzezina on 5th August, 1940.
Henryk remembers:
"My comrade and I arrived at Elm Park station; it was a foggy day and we could not find the airfield, so we asked someone to direct us. When we eventually arrived, I intoduced myself. We were shown our rooms in the Officers Mess and given a batman.
I was told I would go to "B" Flight, comanded by Flight Lieutenant Mungo-Park. After a while the members of the squadron named us "Breezy" and "Sneezy", as it was far easier for them than to pronounce our Polish names; I was also called Henry the Pole. I was 31 years of age at this time, and was married and had 2 sons. My English was absolutely nil when I arrived. I was helped very much by the pilots of 74 Squadron to learn English; H. M. Stephen, Malan, and Mungo-Park would help me with phrases like 'Tally-Ho', 'Pancake', and 'Scramble', but I would always follow my leader. Malan would always say we were to stick together; I flew as his No.2 on many occasions.