Question: When the the military branch of the XXX Corps start wearing khaki?

full_context: Document 1: Afrika Korps: The Afrika Korps or German Africa Corps (, DAK ) was the German expeditionary force in Africa during the North African Campaign of World War II. First sent as a holding force to shore up the Italian defense of their African colonies, the formation fought on in Africa, under various appellations, from March 1941 until its surrender in May 1943. The unit's best known commander was Field Marshal Erwin Rommel.
Document 2: Operation Market Garden: Operation Market Garden (17 -- 25 September 1944) was an unsuccessful Allied military operation, fought in the Netherlands and Germany in the Second World War. The operation was split into two sub-operations:
Document 3: Allied invasion of Italy: The Allied invasion of Italy was the Allied amphibious landing on mainland Italy that took place on 3 September 1943 during the early stages of the Italian Campaign of World War II. The operation was undertaken by General Sir Harold Alexander's 15th Army Group (comprising General Mark W. Clark's Fifth Army and General Bernard Montgomery's British Eighth Army) and followed the successful invasion of Sicily. The main invasion force landed around Salerno on 9 September on the western coast in Operation Avalanche, while two supporting operations took place in Calabria (Operation Baytown) and Taranto (Operation Slapstick).
Document 4: Navy blue: Navy blue got its name from the dark blue (contrasted with white) worn by officers in the British Royal Navy since 1748 and subsequently adopted by other navies around the world. When this color name, taken from the usual color of the uniforms of sailors, originally came into use in the early 19th century, it was initially called "marine blue", but the name of the color soon changed to "navy blue".
Document 5: North African campaign: The North African Campaign of the Second World War took place in North Africa from 10 June 1940 to 13 May 1943. It included campaigns fought in the Libyan and Egyptian deserts (Western Desert Campaign, also known as the Desert War) and in Morocco and Algeria (Operation Torch), as well as Tunisia (Tunisia Campaign).
Document 6: Uniforms of the United States Navy: The Navy first authorized a khaki uniform in 1913 as a practical garment for early naval aviators; they were given permission to wear Marine Corps khaki uniforms with naval insignia, when flying or working on aircraft. Khakis were authorized aboard submarines in 1931 and as a working uniform on all ships ten years later.
Document 7: XXX Corps (United Kingdom): XXX Corps (30 Corps) was a corps of the British Army during the Second World War. The Corps provided extensive service in the North African Campaign at the Second Battle of El Alamein in late 1942, and in the Tunisia Campaign and the Allied invasion of Sicily in 1943, after which it returned briefly to the United Kingdom; the Corps served in the reclamation of France from June 1944 in the Allied Invasion of Normandy, and then served in Operation Market Garden, in the Netherlands, and finally in Operation Veritable in Germany until May 1945.
Document 8: North African campaign: Fighting in North Africa started with the Italian declaration of war on 10 June 1940. On 14 June, the British Army's 11th Hussars (assisted by elements of the 1st Royal Tank Regiment, 1st RTR) crossed the border from Egypt into Libya and captured the Italian Fort Capuzzo. This was followed by an Italian counter-offensive into Egypt and the capture of Sidi Barrani in September 1940 and again in December 1940 following a British Commonwealth counteroffensive, Operation Compass. During Operation Compass, the Italian 10th Army was destroyed and the German Afrika Korps -- commanded by Erwin Rommel, who later became known as ``The Desert Fox ''-- was dispatched to North Africa in February 1941 during Operation Sonnenblume to reinforce Italian forces in order to prevent a complete Axis defeat.
Document 9: Service Dress (British Army): Service Dress was the new style of khaki service dress uniform introduced by the British Army for use in the field from the early 1900s, following the experiences of a number of imperial wars and conflicts, including the Second Boer War. This variant of uniform continues to be worn today, although only in a formal role, as No. 2 Pattern dress.
Document 10: British Army during the Second World War: The pre-war British Army was trained and equipped to be a small, mechanised, professional army. Its main function was to garrison the British Empire. It became evident early in the war that its initial structure and manpower was woefully unprepared and ill - equipped for a war with multiple enemies on multiple fronts. The British Army, an all - volunteer force until 1939, was small in comparison to its enemies at the start of the Second World War in 1939, as it had been in the First World War. By the end of the Second World War, however, over 3.5 million men had served in the British Army.
Document 11: United States Air Force: The first USAF dress uniform, in 1947, was dubbed and patented "Uxbridge Blue" after "Uxbridge 1683 Blue", developed at the former Bachman-Uxbridge Worsted Company. The current Service Dress Uniform, which was adopted in 1993 and standardized in 1995, consists of a three-button, pocketless coat, similar to that of a men's "sport jacket" (with silver "U.S." pins on the lapels, with a silver ring surrounding on those of enlisted members), matching trousers, and either a service cap or flight cap, all in Shade 1620, "Air Force Blue" (a darker purplish-blue). This is worn with a light blue shirt (Shade 1550) and Shade 1620 herringbone patterned necktie. Enlisted members wear sleeve insignia on both the jacket and shirt, while officers wear metal rank insignia pinned onto the coat, and Air Force Blue slide-on epaulet loops on the shirt. USAF personnel assigned to Base Honor Guard duties wear, for certain occasions, a modified version of the standard service dress uniform, but with silver trim on the sleeves and trousers, with the addition of a ceremonial belt (if necessary), wheel cap with silver trim and Hap Arnold Device, and a silver aiguillette placed on the left shoulder seam and all devices and accoutrement.
Document 12: First Battle of El Alamein: The First Battle of El Alamein (1 -- 27 July 1942) was a battle of the Western Desert Campaign of the Second World War, fought in Egypt between Axis forces (Germany and Italy) of the Panzer Army Africa (Panzerarmee Afrika, which included the Afrika Korps) (Field Marshal (Generalfeldmarschall) Erwin Rommel) and Allied (British Imperial and Commonwealth) forces (Britain, British India, Australia, South Africa and New Zealand) of the Eighth Army (General Claude Auchinleck).
Document 13: Red coat (military uniform): Red coat or Redcoat is a historical item of military clothing used widely, though not exclusively worn, by most regiments of the British Army from the 17th to the 20th centuries. From the mid-17th century to the 19th century, the uniform of most British soldiers (apart from artillery, rifles and light cavalry) included a madder red coat or coatee. From 1873 onwards, the more vivid shade of scarlet was adopted for all ranks, having previously been worn only by officers, sergeants and all ranks of some cavalry regiments.
Document 14: Eton College: The long-standing claim that the present uniform was first worn as mourning for the death of George III is unfounded. "Eton dress" has undergone significant changes since its standardisation in the 19th century. Originally (along with a top-hat and walking-cane), Etonian dress was reserved for formal occasions, but boys wear it today for classes, which are referred to as "divisions", or "divs". As stated above, King's Scholars wear a black gown over the top of their tailcoats, and occasionally a surplice in Chapel. Members of the teaching staff (known as Beaks) are required to wear a form of school dress when teaching.
Document 15: First Battle of El Alamein: The First Battle of El Alamein (1–27 July 1942) was a battle of the Western Desert Campaign of the Second World War, fought in Egypt between Axis forces (Germany and Italy) of the Panzer Army Africa (, which included the under Field Marshal () Erwin Rommel and Allied (British Imperial and Commonwealth) forces (Britain, British India, Australia, South Africa and New Zealand) of the Eighth Army (General Claude Auchinleck).
ground_truth: early 1900s
sub_queries: XXX Corps >> military branch Answer: British Army
when did British Army start wearing khaki Answer: early 1900s