It was to feature the first White Walker as black, put lesbian characters at the heart of the plot and make one of Ned Stark’s ancestors mixed race.
The series, in which the main theme was to be colonialism, was being run by writer and producer Jane Goldman — married to TV and radio presenter Jonathan Ross.
But after three years of work, the show — which had the working title Bloodmoon — was suddenly shelved for good this week.
HBO instead announced a different prequel called House of the Dragon, said to be more similar to the original series.
The ten-parter will be based on George R.R. Martin’s book Fire & Blood.
A source said: “HBO were terrified the first prequel would scare hardcore fans. It was very different to the original series, but was very brave and bold.
“The prequel was very woke and subversive. But they’ve decided to go for a script by a bloke and full of dragons.