Per The king's speech Tom Hooper has had a hard time with the historical documentation necessary to make believable the story of King George's struggle against stuttering staged by Colin Firth and Geoffrey Rush. The director, however, was also helped by a very fortunate discovery that took place shortly before shooting began.
In fact, a few weeks before the start of processing, Lionel Logue's nephew, Mark, found a huge box containing the notes from his grandfather, including, of course, those relating to the path carried out with King George.
In addition to Logue's notes, moreover, the box contained about a hundred letters exchanged between King George and his therapist, as well as the one that gave all the impression of being the copy of the speech that His Majesty held on the radio on the occasion of the declaration of war on Germany: the one, in short, with which Hooper's film ends.
From Logue's diary, moreover, Firth personally insisted on inserting the passage in which ours, after the famous speech, took up the King for having prevaricated a bit on the W., including the famous answer: "I had to put some in so they knew it was me". What is called a stroke of luck, in short! Here, in the meantime, you can find our review of The King's Speech.