In 1940, during the
Second World War, he was appointed as Assistant Adjutant & Quartermaster General (chief administrative officer) of the
1st Armoured Division, then commanded by
Major-General Roger Evans, during that division's deployment to France. After the
evacuation from France the division reformed back in England. On 13 May 1941, Keightley, on promotion to the
acting rank of
brigadier, was given command of the
30th Armoured Brigade, part of the
11th Armoured Division, which by this time was commanded by Major-General
Percy Hobart, his former mentor. He was appointed an
Officer of the Order of the British Empire in July 1941. , GOC
X Corps,
Sir Oliver Leese, GOC
Eighth Army, and
Sidney Kirkman, GOC
XIII Corps, all watching an Allied bombing raid on Monte Cassino, 15 March 1944. In late December 1941 he was promoted to acting major-general to become Commandant of the
Royal Armoured Corps Training Establishment. After only five months in this job he was briefly given command on 21 April 1942 of the
11th Armoured Division, which was then based in the United Kingdom and then on 19 May 1942 went to command the
6th Armoured Division and led it with distinction throughout the
Tunisian Campaign, elements landing in
French North Africa in November as part of
Operation Torch. He was made a
Companion of the Order of the Bath for his services in Tunisia and also was awarded the
Legion of Merit by the United States government. His permanent rank was advanced from major to lieutenant colonel in September 1943 and again to colonel in April 1944. In December 1943 he exchanged commands with Major-General
Vyvyan Evelegh, the
General officer commanding (GOC) of the
78th Infantry Division, which had fought alongside the 6th Armoured in Tunisia was then serving in Italy, and which became his first infantry command. He was awarded the
Distinguished Service Order in August 1944 and his success as a commander of both armoured and infantry divisions led to his promotion in August 1944 to acting
lieutenant-general when he was given command of the
British Eighth Army's
V Corps, succeeding Lieutenant General
Charles Allfrey, in Italy. At the age of 43 he was the youngest officer in the
British Army during the Second World War to command a corps in action.
Toby Low, the youngest brigadier in the British Army, was Keightley's Brigadier General Staff (BGS). He commanded this corps during
Operation Olive, the offensive on the Gothic Line in the autumn of 1944, and also during the final
spring offensive in April 1945, when it took a lead role in forcing the
Argenta Gap. The corps moved into
Austria with the surrender of the
German Forces and forces that were fighting on the German side. On 8 May 1945, he signed a demarcation agreement with the Bulgarian
First Army commander, General
Vladimir Stoychev in
Klagenfurt. In
East Tyrol and
Carinthia, Keightley's army received the surrender of the "
Lienz Cossacks" under their leaders
Peter Krasnov,
Kelech Ghirey, and
Andrei Shkuro and the
XVth SS Cossack Cavalry Corps under
Helmuth von Pannwitz. At the
Yalta Conference, the British committed themselves to return Soviet citizens to the
Soviet Union. After consultation with
Harold Macmillan Keightley proceeded to hand over these prisoners and their families regardless of their nationality, including people with French, German, Yugoslav or
Nansen passports. The prisoners were delivered by deceit and force to
SMERSH at
Judenburg; many were executed immediately, the remainder sent to the
Gulag. According to
Nikolai Tolstoy’s ''Stalin's Vengeance'' (2021) In mid-1945, Keightley was appointed
Knight Commander of the Order of the British Empire and nominated to lead a proposed "
Commonwealth Corps" during Operation Coronet, the second stage of
Operation Downfall the plan for the invasion of Japan. The corps was to have been made up of infantry divisions from the
Australian, British, New Zealand and
Canadian armies. The Australian government objected to the appointment of an officer with no experience fighting the Japanese and the war ended before the details of the corps were finalised. ==Post-war==