He was the eldest son of Robert William Hudson who had inherited the substantial family soap business and sold it, and Gerda Frances Marion Bushell. Hudson was educated at Eton College and Magdalen College, Oxford. He entered the Diplomatic Service in 1911, becoming an attaché and First Secretary at the British embassy in Washington. Hudson afterwards served as a diplomat in Russia.
He had a particular interest in farming and was a member of the council of the Royal Agricultural Society.
In March 1939, Hudson was scheduled to visit Germany to discuss improving Anglo-German trade, but in protest against the German violation of the Munich Agreement by occupying the Czech of Czecho-Slovakia on 15 March 1939, the visit was cancelled. Hudson was an appeaser who believed that improving Anglo-German economic relations was the key to saving the peace had very much looking forward to his visit to the Reich.
On 8 March 1939, Hudson met Ivan Maisky, the Soviet ambassador to the court of St. James. Hudson in his account of his meeting wrote that Maisky had told him that he was "quite convinced that we, the British empire, were unable to stand up against German aggression, even with the assistance of France, unless we had the collaboration and help of Russia". Hudson replied that he did not share that assessment, saying that he believed that Britain and France were capable of defeating Germany on their own and did not need the help of the Soviet Union. Maisky in his account of the meeting stated that Hudson had told him that the Chamberlain had "firmly decided to maintain the empire and its position as a great power". Maisky had Hudson saying that Britain wanted allies and that: "Here in London, however, many people assured him [Hudson] that the USSR now did not want collaboration with the Western democracies, that it is inclined more and more to a policy of isolation, and that therefore it was pointless to seek a common language with Moscow". Maisky wrote that Hudson had told him that upcoming visit to Moscow was meant to clarify "do we [the Soviets] want or do we not want a rapprochement and collaboration with London". Maisky concluded: "Hence, Hudson's visit to Moscow could play a large role...Personally, Hudson would desire very much that this orientation moved on the line London-Paris-Moscow". Maisky concluded that Hudson was a very ambitious politician who wanted to be prime minister one day, "but I do not think Hudson could take the general line which he developed in today's discussiojn without the sanction of Chamberlain".
On 23 March 1939, Hudson arrived in Moscow, ostensibly to negotiate an Anglo-Soviet trade treaty, but in fact to seek to improve Anglo-Soviet relations in light of the Danzig crisis. As was usually the case with foreign visitors, Hudson was not allowed to see Joseph Stalin in the Kremlin, and instead negotiated with Maxim Litvinov, the Commissar for Foreign Affairs. Hudson was one of the few ministers in the cabinet who spoke fluent Russian. After meeting him, Litvinov wrote to Stalin: "In view of the rejection of all our previous offers, we have no intention of making any new offers and it is up to others to take the initiative...In particular, we are ready now as we always have been, to co-operate with Britain. We are prepared to look at concrete suggestions". Hudson told Litvinov that the Munich Agreement had occurred because of British rearmament was still not complete, but that Britain was now far more advanced in its rearmament than it been in September 1938 as Hudson stated: "There will not be a second Munich". Litvinov stated that his government had been working for a policy of collective security under the banner of the League of Nations since 1934, and hinted that Stalin was losing interest in this policy. However, Litvinov told Hudson that his government "would be prepared to consult with H.M. Government and other governments regarding all suitable measures of resistance whether diplomatic or military or economic. He made it clear that he had in mind the possibility of resistance by force of arms". Hudson went on to accuse the French Foreign Minister Georges Bonnet of wanting to leave Eastern Europe into the German sphere of influence as the price of keeping France out of another world war.
Hudson's insistence that he was in Moscow to only discuss economic matters and his refusal to discuss Litvinov's suggestions of a military alliance doomed his visit to failure. Hudson told Litvinov that he was not convinced that an Anglo-Soviet military alliance was necessary and at one point angered Litvinov when he told him that Britain could do very well without trade with the Soviet Union. Litvinov accused Hudson of being a bully, saying that such threats to cease trade worked with small powers, and that the Soviet Union was a great power. Hudson negotiated with Anastas Mikoyan, the Armenian Communist in charge of economic matters under Stalin. No agreement was struck as both men sought the best possible economic treaty for their respective nations. Hudson also talked with Vladimir Potemkin, the deputy foreign commissar, where he spoke in general about a wish for an Anglo-French-Soviet alliance meant to deter Germany from choosing war. Hudson told Potemkin the lie that Britain was capable of sending 19 British Army divisions to France at once to face the Wehrmacht (in fact the British Army could only sent two divisions to France in March 1939). Potemkin wrote the Hudson mission was a failure because it "began without serious preparations". Potemkin compared Hudson to the character of Khlestakov, the protagonist of The Inspector General short story by Nikolai Gogol. Potemkin wrote that just as Khlestakov was an unimportant person who persuaded people that he was really the dreaded inspector-general of the Emperor Nicholas I that likewise Hudson was just a hack politician who had no real authority to say anything on behalf of London.
Upon his return to London, Hudson offered a bleak assessment of the Soviet Union in a memo dated 4 April 1939 to the Foreign Secretary, Lord Halifax. Hudson wrote that "except where those [Soviet] interests happen to coincide with ours, that are likely a Government to prove an unreliable ally". Through not an expert in military matters, Hudson stated that he talked at length with the British military, air and naval attaches at the embassy in Moscow whose unanimous opinion was that the Soviet Union had an abysmally weak military and that "the Russians would be unable to wage an offensive without the regime breaking down". Hudson criticised the plans for better Anglo-Soviet relations to create a counterweight to Germany as unfeasible, which led him to argue that appeasement of the Reich was the only realistic solution to the present problems in Europe.
On 17 July 1939, Helmuth Wohlthat, Hermann Göring's right-hand man in the Four Year Plan organisation, visited London to attend the meeting of the International Whaling Conference as part of the German delegation The next day, he and the German ambassador Herbert von Dirksen met Sir Horace Wilson, the Chief Industrial Adviser to the Government and one of the closest friends of Neville Chamberlain to discuss the Danzig crisis. Hudson attended the meetings as an aide to Wilson. On 20 July 1939, Hudson visited the German embassy to meet Dirksen and Wohlthat, acting on his own. Hudson, an extremely ambitious man who loved intrigue, was hoping to score a great success that would help his otherwise stalled career. Hudson kept detailed notes of his meeting at the German embassy with Wohlthat and Dirksen, where accordingly to him, he proposed a solution to the Danzig crisis. Hudson's notes have him saying that in exchange for a German promise not to invade Poland and ending the Anglo-German arms race, there would be a plan for the industrialists running the heavy industry of Germany, Britain and the United States to work together in the economic development of China, Eastern Europe and Africa; of a loan in sum of hundreds of millions for Germany to be floated in the City and on Wall Street; and some sort of plan for the "international governance" of Africa, by which he meant that Germany would given a role in the ruling of the African colonies of the European nations. At the time, it was widely accepted that colonies in Africa were necessary to allow the economies of European nations to function, and a major theme of Nazi propaganda was that it was "unjust" on the Treaty of Versailles to deprive the Reich of its African colonies. The repeated German demands for the return of the former German African colonies were a major issue in Anglo-German relations as the British government had no intention of returning the former German colonies. Hudson ended his account by saying that if only Hitler would just learn to think in economic terms that much was possible.
After his meeting at the German embassy, Hudson was by all accounts in a state of euphoria, and he asked a group of journalists to come to his house to tell them "off-the-record" about what he had done. A preening Hudson-who believed that he had more or less single-handedly saved the world from the threat of another world war with his visit to the German Embassy-showed his notes of his visit to the embassy to the journalists, telling them it was he who just ended the Danzig crisis with his bold proposals for Anglo-German economic co-operation as Wohlthat was definitely interested in what he had to say. Hudson asked the journalists not to publish this story yet, saying more time was needed for his plan to work as Wohlthat had to return to Germany to report on his offer to Göring, who presumably would convince Hitler to accept it. Two of the journalists present took the view that this was not "off-the-record" and decided to publish the story. Hudson who was described by another Conservative MP as "looks as through he just inherited a fortune and has been celebrating in a hot bath" boasted much about what he just done at a dinner party, speaking very loudly about his "peace-saving" plan.
On 22 July 1939, The Daily Telegraph and the News Chronicle both broke the story on their front-pages that Britain just had offered Germany a loan worth hundreds of millions of pound sterling in exchange for not attacking Poland. The public reaction to this story was highly negative with much of the press calling Hudson's proposed loan "Danegeld". In order to stop raids of the Vikings, the kings of England had paid the "Danegeld" ("Dane money") to bribe the Danes not to attack. The term "paying the Danegeld" in England implies weakness and cowardice, that someone would rather bribe an enemy rather than stand up for himself. Much to Hudson's humiliation, Chamberlain told the House of Commons that no such loan was being considered and that Hudson was speaking for himself. Despite the humiliation, Hudson remained convinced that "another Munich" to save the peace was still possible under which the Free City of Danzig (modern Gdańsk) would "go home to the Reich" in exchange for Germany not invading Poland. Hudson kept saying that all he needed was "a little more time" to save the peace..