Game Of Thrones has transformed the lives of some of its actors, the author of the fantasy drama said.
Writer George RR Martin returned to the scene of some of the filming in Northern Ireland on Wednesday.
While Sean Bean was an established actor, others like Kit Harington had only undertaken stage work beforehand and others only school plays.
Martin said: “It has transformed their lives and that is pretty heady stuff and I am glad of it but I don’t really take any responsibility for it.
“It is their own brilliance and their own talents that have done it but it is still pretty amazing to know that because of all the characters I thought up sitting all alone in front of a computer 20 years ago it has had this profound effect on them.”
He praised Northern Ireland’s “marvellous” filming locations, singling out the Co Antrim quarry which stood in for the Nights Watch headquarters and The Wall in the show.
The author said: “The buildings were not just facades, you could actually walk on the balconies and open the door and there would be room behind it.
“Cameras could track in and out and up and down stairs.
“That is a great thing, I have worked on a lot of sets that are just facades.”
He said the wall looked very impressive and big.
“Not as big as my wall as I described it but still pretty big and they had a working elevator, which was amazing.
“They did not have to build the iron cage elevator as I described, so that was an amazing impressive set and I gather they have kept that and it is still a tourist attraction.”
He returned to the National Trust property Castle Ward near Belfast where Winterfell was set.
When she was signed up for Game Of Thrones, Emilia Clarke had one low-budget horror film to her name and a commercial.
Harington had been in London.
Some younger actors had only done school plays before.
Martin said: “It makes me feel very good to know that a television show does have the capacity to change lives for the people that work on it, the actors.”
Game Of Thrones shot its eighth and final series with US network HBO.
Martin was last at Castle Ward during shooting of a pilot to help convince television executives to commission a full series.
He said HBO did not “fool around” and ordered a second season almost as soon as the first was on air as the popularity of the series grew.
Martin added: “We had no idea that they would continue to go up and up and up and the show would be picked up all around the world, would be a huge hit around the world.”
He said that drove sales of his books globally.
“I am in 53 different languages now.
“I think a lot of that is due to the television show and its sets in Northern Ireland.
“In fact we actually have an Irish edition, the first book has been published in Irish and I assume the rest of them are to follow.”