The ending of 'Game of Thrones' earlier this year may have been contentious, but even the most disgruntled fan would have admitted that there was a televisual gap in their lives when it finished.

So the news that a prequel pilot - tentatively titled 'Bloodmoon' by some sources, 'The Long Night' by others - was going into production in Northern Ireland was met with much excitement.

The series was due to be set thousands of years before the events in 'Game of Thrones', and would focus on the origin of the White Walkers during the 'Age of Heroes'. Over the summer, further details emerged (as well as photos from the sets), while Naomi Watts and Miranda Richardson were confirmed to star. Jane Goldman was attached as the writer.

However, it's now emerged that HBO have decided not to go ahead with the prequel series.

Reports suggest that Goldman emailed a letter to the cast yesterday breaking the news, although HBO has declined to comment.

Neither Goldman nor the author of the books, George RR Martin (who has discussed the prequel in the past) have publicly commented.

Needless to say, there are a lot of disappointed fans today.

However, there is light at the end of the tunnel: HBO have green-lit a second prequel in the series. 'House of the Dragon' is set 300 years before 'Game of Thrones' and focuses on the House Targaryen dynasty and its eventual decline.

It's not yet known where the new series will be filmed - but with Sapochnik at the helm (who directed the 'Battle of the Bastards' episode of GoT), it's surely in good hands.