The stories of Prince Rhaegar Targaryen and Lyanna Stark are brought to life in the stage show
The first Game of Thrones stage spin-off has been launched by the Royal Shakespeare Company, and the verdict from most theatre critics is that it's a worthy addition to the epic fantasy franchise.
Game of Thrones: The Mad King, a prequel set shortly before the events of George RR Martin's first book and the all-conquering TV series, officially opened at the RSC in Stratford-upon-Avon this weekend.
The Telegraph awarded four stars to the "spellbinding spectacle", while the Guardian's four-star review said it features "spectacular stagecraft and plenty of modern resonance".
The Times was more lukewarm, giving three stars and saying the play "lacks pace, sex and gore".
Michael Shaeffer plays Aerys II Targaryen, the "mad king" of the play's title
The Game of Thrones origin story is epic in both ambition and execution – it has taken seven years to reach the stage, clocks in at three hours 45 minutes, and features a 36-strong cast.
The characters include younger versions of familiar figures like Ned Stark, Jaime Lannister and Robert Baratheon; and others whose fates were key to the events in the main saga, such as Lyanna Stark, Prince Rhaegar Targaryen and the "mad king" himself, Aerys II Targaryen.
After opening in Shakespeare's home town, the RSC will hope it can go on to replicate the success of other spin-off plays like Harry Potter and the Cursed Child and Stranger Things: The First Shadow, which have both had lengthy runs in the West End and on Broadway.
The Shakespeare connection stems from the fact Martin's novels were heavily inspired by Shakespeare's history plays, especially those about the battles between the houses of Lancaster and York during the Wars of the Roses in the 15th Century.
Game of Thrones' US creator was heavily involved in the play, stationing a representative in rehearsals at all times, and he attended the opening night in Stratford on Saturday.
George RR Martin travelled to Stratford-upon-Avon for the play's opening night
In the Guardian's review, Mark Lawson wrote, external: "Purists will object that, rather than staging Shakespeare-adjacent populist spin-offs, the RSC should be offering its house dramatist's royal dramas plain.
"The counter argument is that hitching on to a cultural juggernaut may bring in new sources of income and audiences."
Audiences will respond differently to the play depending on whether they are already loyal Game of Thrones fans, and Lawson's four-star rating attempted to bridge that gap.