Originally, there was not supposed to be any gap. There was just supposed to be a passage of time, as the book went forward. My original concept back in 1991 was, I would start with these characters as children, and they would get older. If you pick up Arya at eight, the second chapter would be a couple months later, and she would be eight and a half and [then] she'd be nine. [This would happen] all within the space of a book.
But when I actually got into writing them, the events have a certain momentum. So you write a chapter and then in your next chapter, it can't be six months later, because something's going to happen the next day. So you have to write what happens the next day, and then you have to write what happens the week after that. And the news gets to some other place.
And pretty soon, you've written hundreds of pages and a week has passed, instead of the six months, or the year, that you wanted to pass. So you end a book, and you've had a tremendous amount of events — but they've taken place over a short time frame and the eight-year-old kid is still eight years old.
So that really took hold of me for the first three books. When it became apparent that that had taken hold of me, I came up with the idea of the five-year gap. "Time is not passing here as I want it to pass, so I will jump forward five years in time." And I will come back to these characters when they're a little more grown up. And that is what I tried to do when I started writing Feast for Crows. So [the gap] would have come after A Storm of Swords and before Feast for Crows.
But what I soon discovered — and I struggled with this for a year — [the gap] worked well with some characters like Arya — who at end the of Storm of Swords has taken off for Braavos. You can come back five years later, and she has had five years of training and all that. Or Bran, who was taken in by the Children of the Forest and the green ceremony, [so you could] come back to him five years later. That’s good. Works for him.
Other characters, it didn’t work at all. I'm writing the Cersei chapters in King's Landing, and saying, "Well yeah, in five years, six different guys have served as Hand and there was this conspiracy four years ago, and this thing happened three years ago." And I'm presenting all of this in flashbacks, and that wasn't working. The other alternative was [that] nothing happened in those five years, which seemed anticlimactic.
The Jon Snow stuff was even worse, because at the end of Storm he gets elected Lord Commander. I'm picking up there, and writing "Well five years ago, I was elected Lord Commander. Nothing much has happened since then, but now things are starting to happen again." I finally, after a year, said "I can't make this work."