HBO was reportedly going to produce a Game of Thrones prequel series. Showrunner Jane Goldman (known for her most recent work in Kingsman: The Secret Service) was set to write the series with S.J. Clarkson as director. Naomi Watts (The Impossible) was planned as the lead for the series, following Naomi Ackie (Lady Macbeth), Denise Gough (Robin Hood), and Josh Whitehouse (The Receptionist). This Game of Thrones prequel (which was believed to be name The Long Night for its pilot episode) was exclusively set to take place 1000 years before the events in the primary series of Game of Thrones. They were to explain the lineage of the House of Stark and the history behind Westeros and its connection with the White Walkers.
The reason for the cancelation boiled down to a few reasons. The prequel show did indeed shoot a full pilot episode in Ireland around June, according to an article by Entertainment Weekly, but ultimately had issues during the production phase. It was also due to an over-extended post-production process and an expensive pilot on a whooping 10 million budget, according to Deadline. Another reason why corporate executives decided to pulled the plug is the fact that HBO had just recently decided to pursue another Game of Thrones prequel series and ordered a series be produced according to The Hollywood Reporter. The script for this prequel called the ‘House of the Dragon’ is based on George R.R Martin’s novel Blood & Fire and written by writer Ryan Condal whose written for movies including Rampage and television shows such as Colony.
The details pertaining to the newly annoucnced series involve Miguel Sapochnik and Vince Gerardis both whom were involved with the original running of the Game of Thrones franchise. In Sapochnik’s case, directing (from which he received an Emmy award for his work) and Gerardis as executive producer. Both Sapochnik and Gerardis plan to executive producer the show while Miguel Sapochnik doubles as a co-showrunner with writer Ryan Condal. The progression of the series will be approximately a 10-episode and will take place about 300 years before the events to the original show and will explain the history within the House of Targaryen and the Targaryen Civil War.