George RR Martin confirms the first Game of Thrones prequel will be called ‘The Long Night’

Naomi Watts has been cast in the show

George RR Martin has revealed the title of the first of the highly-anticipated Game of Thrones prequel shows.

He confirmed the series will be entitled The Long Night in a blog on his website.

Last week, Oscar-nominated Australian actress Naomi Watts was cast in he show.

"I could not be more excited," said Martin in the blog. "Welcome to Westeros, Naomi".

The series will be written by Jane Goldman, who adapted both Kingsman and Kick-Ass for the big screen.

"She and her team are busy in London right now, neck deep in casting, and I expect some more names will be announced soon," Martin added.

He also teased the other prequels, but didn’t give anything away.

"Meanwhile, there are still a couple of other possible prequels in active development. I can’t tell you the subject matter of those projects, no, sorry, wish I could."

HBO have up to five Game of Thrones spin-offs currently being developed.

The 'Long Night' refers to a period 8,000 years before the current show. In the third episode of the first season, Old Nan gave Bran Strak this chilling description of it: "Thousands of years ago, there came a night that lasted a generation. Kings froze to death in their castles, same as the shepherds in their huts; and women smothered their babies rather than see them starve, and wept, and felt the tears freeze on their cheeks... In that darkness the White Walkers came for the first time. They swept through cities and kingdoms, riding their dead horses, hunting with their packs of pale spiders big as hounds."