'Lemmie' Le Mesurier was born on 27 June 1914 in Cape Province, undertaking survey work after attending the University of Cape Town.

In March 1936, he joined the Cadet Company of the Special Service Battalion, but in September transferred to the Military College as a Permanent Force Cadet, entering the SAAF. He became a flying instructor in June 1939 and from March to July 1940 was acting commander of Baragwanath FTS.

On 8 November he joined 1 SAAF Squadron in East Africa and took temporarily command over the unit, which had lost its commander, Major Schalk van Schalkwyk, on 6 November.
He arrived with three replacement Gladiators from 2 SAAF Squadron in Kenya. One of the (N5813) flown by Lieutenant B. R. Dimmock was shot down by over-eager Sudanese gunners and made a forced landing on an island in the Nile.
Le Mesurier became 'A' Flight commander in December 1940, acting as temporary commanding officer again during February-March and June 1941.

Early on 27 December, six CR.42s from the 412^a Squadriglia made a strafing attack on Gedaref. The Italian formation is believed to have compromised Capitano Antonio Raffi, Sottotenenti Niso Provinciali, Filippo Sola and Fiorindo Rosmino, and two other pilots. They saw two landing grounds, strafed a single aircraft on one and a detachment of Indian cavalry, which was exercising on the other.
Five Gladiators from 1 SAAF’s detachment at Azzoza were ordered to scramble, but only three got off, these being directed on to two more CR.42s, which were covering the strafing aircraft. Attacking these, the Gladiators cut off the rearmost aircraft, which attacked them head-on with great desperation. Captain Le Mesurier’s guns jammed as soon as he began firing and an explosive bullet from the Fiat struck the propeller of Lieutenant Thomas Condon’s aircraft (Gladiator N5789). Despite this, Condon shot down the Italian fighter in flames five miles east of Gedaref, the pilot, believed to be Sottotenente Sola, being killed.

On 24 January 1941, Italian raids were made on troops in northern Eritrea, and also on concentrations near Metema and Gallabat.
In the morning (take-off after 06:30), Lieutenant John Hewitson (Hurricane V7655) strafed a Ca.133, which he found in a clearing 40 miles west of Agrodat.
At 11:30, Captain Le Mesurier with Lieutenants John Coetzer and E. A. Jarvis took off from Sabdaret in Gladiators, joining up with two Hurricanes (Lieutenants Hewitson and Leonard le Clues Theron) for another raid on Agordat. The Gladiators ran into two CR.42s at the enemy airfield. Captain Le Mesurier and Lieutenant Coetzer chasing one for about 24km, firing at intervals, before it finally outran them. Le Mesurier retuned and claimed it as a damaged. Lieutenant Jarvis engaged the other for about 15 minutes but failed to register any damage on it while the Fiat’s fire hit his top wing.
Italian fighters patrolling over the front seem to have claimed two victories during the day.
The South African fighters were back at 12:05

At 10:15 on 3 February, Captain Le Mesurier and Lieutenant Leonard le Clues Theron took off for a patrol over Gura.
At 11:10, they intercepted two CR.42s attacking a RAF bomber near Gura. Le Mesurier shot down one of the attackers.
This was Sottotenente Vincenzo D'Addetta of the 412^a Squadriglia who reportedly was lost in a battle over Gura with eleven bombers and five escorting fighters.

Around noon on 5 February four Hurricanes and two Gladiators from 1 SAAF Squadron flew an offensive patrol over Asmara, stepped up in echeloned pairs, when they saw six CR.42s also stepped up in pairs, on the port beam. The SAAF fighters climbed to attack and the CR.42s tried to evade into clouds. Lieutenants Robin Pare and White were unable to obtain conclusive results. Captain K. W. Driver, in a Hurricane, attacked the leading one head on, and hit the engine, the pilot breaking away and making for Asmara. Driver fired again and the Fiat crash-landed near the airfield. Lieutenant John Coetzer, in one of the Gladiators, claimed a second in a stern attack, firing three bursts before it dived into a cloud. Pulling up and over the cloud, he saw the CR.42s crash in flames near a road, around 4.8km east of Asmara around 12:45. A third was claimed by Captain Le Mesurier, also in a Hurricane, but this could have been confused with Coetzer's claim.
One Gladiator was hit in the engine, but managed to land at Agordat.
Italian records show that one CR.42 crash-landed badly damaged and with the pilot slightly wounded, while a second from 412^a Squadriglia was shot down, the Sottotenente Giovanni Consoli bailing out. He was badly wounded and died later that day.

After a short spell as temporarily OC of 1 SAAF Squadron, Captain Le Mesurier left command of the unit on 16 March when Major T. Ross Theron arrived.

On 12 July 1941, he returned to the Union.

He returned to the squadron on 24 April 1942, becoming commanding officer on 10 May 1942.

A Stuka raid approached at 18:35 on 3 July 1942 and twelve Hurricanes of 274 Squadron were scrambled (18:35-19:35) to provide top cover to 1 SAAF Squadron which was intercepting the incoming raid. A large formation was seen, escorted by seven Bf 109F-4trops of II./JG 27. The South Africans attacked the bombers while 274 Squadron held off the escorts and Flight Sergeant J. W. Neil (Hurricane IIc BP326/T) managed to claim one of them damaged west of El Alamein. Against the Stukas, 1 SAAF Squadron had a field day and at 19:00 and 6 miles south of El Alamein claimed 13 Ju 87s shot down, three damaged and one destroyed Bf 109F and a second damaged:
1 Ju 87B destroyed and 1 Bf 109F destroyed by Lieutenant ‘Tony’ Biden (BG672/AX-P)
3 Ju 87s destroyed and 1 Bf 109F damaged by Lieutenant R. J. P. ‘Moon’ Collingwood (Z2503/AX-E)
1 Ju 87 damaged by Lieutenant G. R. ‘Ray’ Connell (…173/AX-J)
2 Ju 87s destroyed by 2nd Lieutenant J. H. ‘Harry’ Gaynor (BG968/AX-G)
1 Ju 87 destroyed by Major Le Mesurier (BG971/AX-V)
1 Ju 87 destroyed by Lieutenant A. D. ‘Jerks’ Maclean (Z5348/AX-M)
1 Ju 87 destroyed by 2nd Lieutenant H. Marshall (Z4959/AX-C)
2 Ju 87s destroyed and 1 Ju 87 damaged by Captain P. C. R. Metlerkamp (BG764/AX-W)
1 Ju 87 damaged by Lieutenant Tom Phillips (…356/AX-A)
1 Ju 87B destroyed by Lieutenant I. R. R. Pryde (Z5606/AX-Z)
1 Ju 87 destroyed by 2nd Lieutenant C. R. Sinclair (Z5335/AX-U)
Hit by a stray bullet from one of the Ju 87s, Lieutenant Connell had to crash-land at Burg el Arab (his fighter was damaged as a Cat. II). This was the only damaged fighter from the Allied units.
The escorting Messerschmitt pilots claimed three Hurricanes shot down when Oberfeldwebel Alfred Schulze of 4./JG 27 claimed a P-40 at 18:06 south-west of El Alamein, Feldwebel Alfred Heidel of 4./JG 27 claimed a P-40 at 18:10 south-west of El Alamein and Oberleutnant Ernst Börngen f 5./JG 27 claimed a P-40 at 18:12 west of El Alamein.
The fighting continued all the way back to the German base at Fuka, during which Lieutenant Biden claimed a Bf 109 shot down. Of the 13 dive-bombers claimed shot down, army observers confirmed nine from the ground within 30 minutes. However, only five are recorded as shot down during the day:
Ju 87R-2 WNr. 6122 S7+KK from 2./StG 3 reportedly shot down by AA 10km south of El Alamein; Ritterkreuzträger and Staffelkapitän Leutnant Josef Wenigmann and Gefreiter Michael Kugler KiA
Ju 87R-4 WNr. 6272 S7+EK from 2./StG 3 reportedly shot down by Hurricanes 10km south of El Alamein; Feldwebel Peter Spies PoW and Unteroffizier Josef Zeilbauer KiA
Ju 87R-2 WNr. 6199 S7+JL from 3./StG 3 reportedly shot down by Hurricanes south of El Alamein; Oberleutnant Rudolf Schnurawa and Feldwebel Otto Naumann KiA
Ju 87R-2 WNr. 5690 from 3./StG 3 reportedly shot down by Hurricanes south of El Alamein; crew safe
Ju 87D-1 WNr. 2490 from 5./StG 3 reportedly shot up by Hurricanes south of El Alamein and crash-landed on return at Bir el Abd; Unteroffizier Friedrich Wolf safe and Feldwebel Heinz Renner KiA

Eight Bf 109F-4 trops of I./JG 27 took off to escort Stukas at 17:25 on 4 July, joined by eight from II.Gruppe. Hurricane IIcs of 80 Squadron, several of them flown by attached 92 Squadron pilots, were scrambled (17:30-18:30), covered by 1 SAAF Squadron.
A large combat commenced and Leutnant Hans-Arnold Stahlschmidt (2./JG 27) and Feldwebel Günther Steinhausen (1./JG 27) attacked the South African top cover at 17:05 with Leutnant Stahlschmidt claiming one Hurricane south-west of Burg el Arab and Feldwebel Steinhausen a second 20 kilometres south-south-east of El Alamein. Oberleutnant Ferdinand Vögl claimed a third at 17:18 south-east of El Alamein but due to lack of witnesses, this was not confirmed. Bf 109F-4 trop WNr. 8696 Red 9 from 2./JG 27 was shot down in combat with Hurricanes in the El Alamein area with Leutnant Friedrich Körner becoming PoW but since there were many combat during the day in the area, it is not known if this fighter was lost in this combat.
The Hurricanes attacked the Ju 87s and totally claimed five destroyed, three probables and five damaged:
Flight Sergeant R. W. Blades (92 Squadron) in BE713/EY-H claimed one Ju 87 destroyed 10 miles south of El Alamein
Pilot Officer J. M. V. Carpenter (92 Squadron) in BN389/EY-C claimed one Ju 87 damaged south of El Alamein
Pilot Officer W. L. ‘Red’ Chisholm (92 Squadron) in BN291/EY-S claimed one Ju 87 damaged south of El Alamein
Pilot Officer E. H. Hill (92 Squadron) in BE141/EY-J claimed one Ju 87 damaged 10 miles south of El Alamein
Pilot Officer Morgan (92 Squadron) in BM991/EY-V claimed one Ju 87 probably destroyed south of El Alamein
Flight Lieutenant J. M. Morgan (92 Squadron) in BM984/EY-Z one Ju 87 destroyed and a second damaged south of El Alamein
Pilot Officer D. K. Ryder (92 Squadron) in BE553 claimed one Ju 87 probably destroyed south of El Alamein
Pilot Officer W. A. Wales (92 Squadron) in BM974/EY-B claimed one Ju 87 destroyed south of El Alamein
Sergeant G. T. Pratley (80 Squadron) in BE542/EY-E claimed one Ju 87 probably destroyed 10 miles south of El Alamein
Sergeant J. D. Robb (80 Squadron) in BN462/EY-R claimed one Ju 87 damaged 10 miles south of El Alamein
Flight Lieutenant J. A. Sowrey (80 Squadron) in BE564/EY-A claimed two Ju 87s destroyed 10 miles south of El Alamein
Major Le Mesurier (1 SAAF Squadron) in BG971/AX-V claimed one Ju 87 probably destroyed over the El Alamein line after 17:35
1 SAAF Squadron also claimed two of the escorting Bf 109s when Captain P. C. R. Metlerkamp (BE703/AX-R) claimed one 15 miles south-south-west of El Alamein at 18:10 and Lieutenant A. D. ‘Jerks’ Maclean (Z5348/AX-M) claimed a second as a probable 10 miles south-west of El Alamein at 18:05.
The Hurricanes suffered heavily however and four were lost with a fifth damaged:
BE564/EY-A of 80 Squadron collided with a Ju 87 and Flight Lieutenant Sowrey parachuted
BE141/EY-J of 80 Squadron was shot down by Bf 109s in the El Imayid area with Pilot Officer Hill (92 Squadron) safe
BM974/EY-B of 80 Squadron was shot-up by Bf 109s in the El Imayid area with W. A. Wales (92 Squadron) safe
BG971/AX-V of 1 SAAF Squadron was shot down by Bf 109s near El Imayidat 18:25 with Major Le Mesurier WiA
BE200 of 1 SAAF Squadron was shot down by Bf 109s and crash-landed (Cat. II) and Lieutenant W. F. Powell returned later.
Despite the heavy claiming of Ju 87s, it’s been difficult to verify these claims since according to Luftwaffe records the only loss during the day was Ju 87D-1 WNr. 2547 from 6./StG 3, which was lost in combat with Hurricanes 30 kilometres south-east of El Alamein with Leutnant Johannes Suckow PoW and Unteroffizier Wilhelm Printz KiA but as with the above mentioned lost Bf 109 there were many combat during the day in the area.

At 10:00 on 28 October, Hurricane IIcs from 1 SAAF Squadron, escorted by 33 Squadron Hurricane IIcs, carried out a patrol in the El Alamein area during which eight Bf 109s attacked the latter unit and forced its aircraft to lose height. The Germans then attacked the South Africans from up-sun, Major Le Mesurier’s aircraft being hit in six places. As he turned, he blacked out and went into a spin. Recovering from this, he was able to regain base.
One fighter (identified as a Spitfire Vc) was claimed during the morning by Hauptmann Wolf-Dietrich Huy of 7./JG 77.

On 14 November 1942 he returned to the Union, medically unfit for further operational flying, where he was advised of the award of a DFC on 23 April 1943.

He served as Acting Senior Flying Instructor at Waterkloof.

He travelled to England to attend 5 ECFS course and collect his medal.

On 8 July he was killed in a flying accident in a mid-air collision in Master III W8453 while practicing dive-bombing on the Hilmarton Bombing Range, with Flight Lieutenant Lewis. Two Americans were also killed in the other aircraft, Oxford V3830.

Although listed as having six victories, this appears to have been an amalgam of all his claims, the total of those confirmed being three.

Le Mesurier had 1 biplane victory and a total of 3 destroyed at the time of his death.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1941
	24/01/41		1	CR.42	Damaged	Gladiator II		East Africa	1 SAAF Squadron
1	03/02/41	11:10	1	CR.42 (a)	Destroyed	Gladiator II		airfield S Gondor	1 SAAF Squadron
2	05/02/41	12:45-	1	CR.42 (b)	Destroyed	Hurricane I		Asmara	1 SAAF Squadron
	1942
3	03/07/42	19:00	1	Ju 87 (c)	Destroyed	Hurricane II	BG971/AX-V	6m S El Alamein	1 SAAF Squadron
	04/07/42	17:35-	1	Ju 87 (d)	Probable	Hurricane II	BG971/AX-V	El Alamein line	1 SAAF Squadron

Biplane victories: 1 destroyed, 1 damaged.
TOTAL: 3 destroyed, 1 probable, 1 damaged.
(a) Sottotenente Vincenzo D'Addetta of the 412^a Squadriglia KIA.
(b) 1 SAAF Squadron claimed three CR.42s in this combat and got a Gladiator damaged in this combat. Italian records show that two CR.42s were shot down with one wounded pilot and one dead.
(c) Claimed in combat with Ju 87s from StG 3, which lost 5 Ju 87s. 1 SAAF Squadron claimed 13 Ju 87s and 3 damaged with 1 Hurricane damaged.
(d) Possibly claimed in combat with Ju 87s from StG 3, which lost 1 Ju 87s. 80 and 1 SAAF Squadron claimed 5 Ju 87s, 3 probables and 5 damaged with 1 Hurricane lost in a collision (pilot safe).

Sources:
Aces High - Christopher Shores and Clive Williams, 1994 Grub Street, London, ISBN 1-898697-00-0
A History of the Mediterranean Air War 1940-1945: Volume Two – Christopher Shores and Giovanni Massimello with Russell Guest, Frank Olynyk & Winfried Bock, 2012 Grub Street, London, ISBN-13: 9781909166127
Dust Clouds in the Middle East - Christopher Shores, 1996 Grub Street, London, ISBN 1-898697-37-X
Gloster Gladiator Home Page - Alexander Crawford.
Springbok Fighter Victory: East Africa Volume 1 1940 – 1941 – Michael Shoeman, 2002 African Aviation Series No. 11, Freeworld Publications CC, ISBN 0-958-4388-5-4