The original Game of Thrones series quickly became a massive hit for HBO after launching in 2011 and eventually went on to become the premium network’s biggest series in history. Following the record-breaking final season earlier this year, HBO moved several prequel and spinoff ideas into various stages of development. It looked as though the future of HBO was going to be rooted in the Game of Thrones franchise, but that seems a lot less likely now. The untitled Game of Thrones prequel series starring Naomi Watts, which had already shot a pilot, was passed on by the network, killing the story before it even started.

According to a new report from Deadline, HBO has opted not to move forward with the first Game of Thrones prequel series from writer Jane Goldman. Of the various Game of Thrones series at HBO, this prequel was easily the furthest along, meaning that the first spinoff probably won’t actually air for some time.

This prequel was set to take place thousands of years before the events of the main Game of Thrones series, dealing with issues of power, race, and the introduction of the White Walkers. In addition to Watts, the cast of the prequel included Josh Whitehouse, Miranda Richardson, Jamie Campbell Bower, Toby Regbo, Georgie Henley, Alex Sharp, Naomi Ackie, Marquis Rodriguez, John Simms, Richard McCabe, John Heffernan, And Dixie Egerickx.