Game Of Thrones: Learn the history of Westeros in new George RR Martin book

The back story to fictional kingdom Westeros is explained in The World of Ice and Fire: The Untold History of Westeros and the Game of Thrones, which features text by Martin and illustrations from a range of fantasy artists, including Iron Throne painter Marc Simonetti.

"It was bigger than anticipated," the author said of his 300-page book. "I start these things that I think won't take much time and they grow and grow."

The 66-year-old writer dropped some hints about what fans can expect from the book when in New York recently.

"The 'world' is big and getting bigger," he told MTV. "The new book explains thousands of years of history surrounding Westeros, Essos and the other nearby and faraway lands. However, there’s more to reveal in a later book."

New religions will be introduced and readers will also learn how to birth a dragon (crucial life knowledge, you understand).

Amazon describes the new release as "lavishly illustrated" with thrilling accounts of "epic battles, bitter rivalries and daring rebellions".

Fans would not be blamed for wishing that Martin would just knuckle down and finish promised sixth novel, The Winds of Winter, which as of yet has no release date.

Martin's first A Song of Ice and Fire book was published in 1996 and the saga has slowly developed cult status ever since.

His novels were propelled into mainstream global success when HBO adapted them into the hugely popular TV series, Game of Thrones.

The US network has not announced a premiere date for the fifth season but reports suggest it might be returning in April 2015.