Lieutenant General Sir Frank Noel Mason-MacFarlane, KCB, DSO, MC & Two Bars (23 October 1889 – 12 August 1953) was a senior British Army officer, administrator and politician who served as Governor of Gibraltar during the Second World War.

In his favourite Ford V-8 coupe, Mason-MacFarlane went out to personally observe the Anschluss after the Oberkommando der Wehrmacht denied to him that it was happening and to investigate the German-Czechoslovak border region during the May Crisis.

[13] On 3 August 1938, Henderson reported to the Foreign Secretary, Lord Halifax that up to 8 German divisions had been sent to the German-Czechoslovak border, but he believed that this was a bluff on the part of Hitler to pressure President Edvard Beneš of Czechoslovakia to grant autonomy to the Sudetenland.

Mason-MacFarlane recognised he was being used as a pawn in an internal German policy dispute, writing "any bungling of an attempt to interfere from without with Germany's domestic politics during Hitler's lifetime would most assuredly lead to exactly what we all wished to avoid".

[15] On 21 August 1938, Mason-MacFarlane met an agent of Colonel Hans Oster, the deputy chief of the Abwehr, who told him of Fall Grün (Case Green), the plan to invade Czechoslovakia.

[17] In late August, Mason-MacFarlene submitted a report to Henderson declaring that if Britain made an alliance with Czechoslovakia that this offered 'an outside possibility that we might avert or at any rate postpone catastrophe".

[18] Mason-MacFarlane was sent by Henderson and Wilson to deliver a message to text of Hitler's Bad Godesberg ultimatum to Prague but the German-Czechoslovak border was closed, forcing him to cross the frontier by a forest path.

[7][19] While crossing the frontier, he was caught up in the barbed wire, and a nervous young Czechoslovak Army soldier helped untangle him instead of challenging him, an experience that left with the conviction that Czech morale was poor.

[21] Upon reaching Prague and after delivering the message to President Beneš, Mason-MacFarlane telegraphed a cable to London stating based upon what he had seen in the Sudetenland that the Czechoslovak Army was suffering from low morale and would swiftly collapse if Germany invaded.

[23] General Sir Henry Pownall, the Director of Military Operations and Intelligence wrote in his diary: "We were much influenced by the views of Mason-Macfarlane who flew over from Berlin that afternoon [27 September] – he has done noble work.

[26] On 2 January 1939, Ogilvie-Forbes very strongly endorsed a report from Mason-MacFarlane stating that the German economy was being organised for "total war" and Hitler would almost certainly invade one of his neighbours in 1939.

[30] After the German occupation of the Czech half of the rump state of Czecho-Slovakia on 15 March 1939, Mason-MacFarlane's reporting from Berlin took a very hawkish tone and several times he suggested a "preventive war" against Germany.

Such blockade can only be rapidly effective if Germany's eastern front is on or close to her present frontier and if she has to gain and hold resources essential to her powers of resistance".

[12] Parts of the Colvin report were genuine, as it presented verbatim the orders issued by Field Marshal Walther von Brauchitsch on 27 March 1939 for the Wehrmacht to move divisions to the Polish border.

[12] On 29 March, Mason-MacFarlane in support of Colvin that he it was established that arms depots were set up in East Pomerania and stated that "well informed army and SS sources" indicated to him that an invasion of Poland was planned for late April 1939.

[31] In London, Colvin warned that Hitler was planning to conquer Poland, then Lithuania, in order to plunder their resources to prepare for "the ultimate goal" of a war to destroy the British empire.

[39] General Gerhard von Schwerin, seeing Mason-MacFarlane's remarks as a way to persuade Hitler not to launch a "premature" war in 1939, met him to ask if he was speaking on behalf of himself or the British government.

[42] The Canadian historian Wesley Wark wrote: " Mason-Macfarlane represents the extreme case of a military attache who abandoned the uses of ambiguity in favour of single-minded and reductive reporting that made no effort to balance the strengths and weaknesses inherent in a military situation, or the gains and losses implied by a British response...He was influential, as we have seen, in the British decision not to back Czechoslovakia at the height of the Munich Crisis.

[46] Mason-MacFarlane briefly served as General Officer Commanding (GOC) of the 44th (Home Counties) Division, a Territorial Army (TA) formation, from April to June 1941, before being appointed Head of the British Military Mission in Moscow, shortly after the German invasion of the Soviet Union.

[47] Appointed on 24 June 1941 and arriving in Moscow on 14 July 1941 to be greeted as a guest of honour by Joseph Stalin at the Kremlin, Mason-MacFarlane had great hopes of Anglo-Soviet cooperation, which were soon dashed as he learned that the xenophobic Soviet regime regarded him as a spy.

[49] Mason-MacFarlane was Governor of Gibraltar from 31 May 1942 to 14 February 1944, and witnessed the air crash there on 4 July 1943, which took the life of his friend the Polish Prime Minister Władysław Sikorski.

In January 1944, he recommend that the Allies force King Victor Emmanuel III, who was extremely unpopular with the Italian people, to abdicate in favour of his son Crown Prince Umberto.

[54] Both the U.S. President Franklin D. Roosevelt and even more so the British Prime Minister Winston Churchill did not wish to press too strongly for the king to abdicate on the grounds that he still commanded the loyalty of what was left of the Italian armed forces.

[56] Greenfield who had been expecting "Mason-Mac" to be a conservative was surprised to find that for a British general he was a "remarkably liberal-minded man" who had much sympathy with the hopes of ordinary people for a better world after the war.

[61] By letting the CLN leaders meet in Rome, instead of keeping them out of the Eternal City as Churchill wanted, Mason-MacFarlane was quite consciously settling the crisis in motion.

[58] To resolve the crisis, Mason-MacFarlane first went to the Grand Hotel where the Roman leaders of the CLN were staying and learned from them that the moderate socialist Ivanoe Bonomi was an acceptable choice as prime minister.

[57] Cadogan wrote that Mason-MacFarlane had failed grievously in his duties, writing that he should have "put the brake on hard" and told the CLN leaders that they had to accept Badoglio as prime minister.

[62] Churchill initially tried to restore Badoglio as prime minister, writing in a telegram to Stalin, seeking his support: "Since when have we admitted the right of Italians to form any government they please?

"[57] From Rome, Macmillan reported to Churchill that it was impossible "to put Humpty Dumpty in his place again after our officers, MacFarlane and Sir Noel Charles have allowed him to tumble off again".

The 2016 novel Midnight in Berlin by James McManus features as its hero Colonel Noel Macrae, "a thinly disguised and heavily romanticized version" of Mason-MacFarlane.