Jack Gleeson (Joffrey Baratheon) received a letter from author George R.R. Martin after the show aired, stating: "Congratulations on your marvelous performance. Everyone hates you!"
According to author George R.R. Martin, Peter Dinklage was the one and only choice to play Tyrion, and no other actors were auditioned. Dinklage has been nominated eight consecutive times (once for each season) for the outstanding supporting actor in a drama series at the Emmys. He won for the first, fifth, seventh and eighth season, setting a new record for most wins in the outstanding supporting actor category for the same role.
According to Kit Harington (Jon Snow), his performance in the rejected pilot episode was so bad that the creators often jokingly threaten to release scenes of it on the internet if he complains too much.
Author George R.R. Martin was approached several times with offers to adapt his (still unfinished) book series "A Song of Ice and Fire" into a movie, but he rejected them all, as he thought his books were much too expansive to be made into a movie. He had purposely written them to be virtually unfilmable, and he also declined offers to adapt only certain storylines from the book. When David Benioff and D.B. Weiss told him that they wanted to make a series out of it, he asked them who they thought Jon Snow's mother could be. Satisfied with the answer, he agreed to sell the rights to the book. The two showrunners later admitted that they tricked HBO into greenlighting the series by convincing them that it was mostly about human drama and character interactions, and could therefore be produced relatively cheaply. They had correctly guessed that none of the studio executives had actually read all of the 4000 pages that Martin had written at the time, and that they had no idea of the expensive scenes that were to come in the future.
Series author George R.R. Martin reported on his blog that after the filming of the episode in which Sansa's direwolf Lady is executed, the dog that played Lady, a Northern Inuit named Zunni, was adopted by Sophie Turner (Sansa).