Kit Harington has launched a vociferous attack on all critics of Game of Thrones, saying they know nothing.

Harington, who plays Jon Snow in the fantasy juggernaut which returned for its last ever season this week, has said he feels “defiant” about the show and that anyone who feels let down by it “can go fuck themselves.”

Speaking to Esquire, he said: “I don’t mean to sound mean about critics here – but whatever critic spends half an hour writing about this season and makes their [negative] judgment on it, in my head they can go fuck themselves.”

He added that no one on the outside can have any idea “how much work was put into this … how much people cared about this … how much pressure people put on themselves.” He discussed the many sleepless nights had by the show’s crew to ensure fans are left satisfied by its ending.

Since 2011, Game of Thrones has become a smash-hit for HBO and Sky. The premiere of the final season broke HBO ratings, with 17.4m viewers in the US alone. Around 200,000 people in Britain stayed up to watch the show live at 2am on Sunday night.

Harington also admitted that he failed to see the show’s appeal entirely at first: “When I read the pilot way back in 2009, I remember thinking, What is this crock of shit? I don’t understand this. I’m going to have to read this again. And I read it again, and I’m like, I still don’t get this shit at all. I think it’s kind of weird, but it’s HBO and alright, let’s do it.”