The actors are playing real-life soldiers who formed the regiment (Picture: BBC/Kudos/Robert Viglasky)

While TV viewers across the nation might be used to watching celebrities test their mental and physical limits in Channel 4’s SAS programme, a brand new BBC drama – SAS: Rogue Heroes – will take audiences all the way back to the formation of the historic regiment.

The Special Air Service (SAS) is a special forces unit in the British Army, which was first formed in the 1940s during the Second World War.

It was founded as a regiment by Sir David Stirling, which was disbanded following the war in 1945.

However, it was reinstated in 1947 and has been going ever since, with 102-year-old Mike Sadler (played by Tom Glynn-Carney) now the last surviving member of the original squad.

With other cast members in the drama including Sex Education’s Connor Swindells, Skins star Jack O’Connell and Game of Thrones actor Alfie Allen, here’s what you need to know.

Who were the real SAS: Rogue Heroes?

SAS: Rogue Heroes is based on the true story about how the Special Air Service was first formed during the Second World War.

The founding members of the SAS are depicted in the series – David Stirling, a Scottish officer in the army and a mountaineer; Paddy Mayne, a British Army officer who was also an amateur boxer and a lawyer; and Jock Lewes, who was the founding principal training officer and invented the Lewes bomb.

Stirling was the founder and creator of the regiment, which came into being in 1941.

While speaking at a screening of the drama, creator Steven Knight – who also created Peaky Blinders – emphasised that he strove to maintain the ‘real story’ of these men and the formation of the SAS.

‘What I didn’t want to do is make it fit fiction, I wanted to try to keep it real,’ he said.

Swindells’ character, David Stirling, was the founding commander (Picture: Kudos/BBC/Banajay)

A memorial statue in honour of Sir David Stirling can be found near Stirling, Scotland. (Picture: Wayne Hutchinson/Farm Images/Universal Images Group via Getty Images)

‘In the forthcoming episodes, there’s lots of failure and disaster and characters who, as a dramatist, you would love to keep going but they don’t. So I’ve chosen that when that character dies and it’s a shock, and hopefully, it will be quite effective.’

One scene in particular was taken from true life but had never been written down.

‘I met Mike Sadler, who was the last surviving member of the original SAS is now 102, he was 99 when I met him,’ Knight said.

‘He told me the story that he and Stirling were in a bar in Paris, and somebody said, “You can’t use this table,” and the hand grenade was a real hand grenade so to make it realistic I turned it into a dummy hand grenade.

West is soon set to appear in season five of The Crown as Prince Charles (Picture: Kudos/BBC/Banajay)

‘They literally had to leave and run because they were beyond reason.’

Producer Karne Wilson added that it’s ‘really important’ that viewers remember they’re watching the stories of real people.

‘We have taken that very seriously. We have been in touch with all surviving members and families. We have tried to do everything as authentically as possible,’ she said.

‘We sought the advice of the SAS Regimental Association, which supported through the process.

Sofia Boutella stars in the series as Eve (Picture: Sophie Mutevelian/Kudos/BBC/Banajay)

‘I think we can only do what is in our gift with the information that we’ve got, but I think with Ben’s book, with the research that Steve’s done with the team, the way they approached authenticity.’

She expressed her hope that audiences are aware that the makers of the series have ‘taken the authenticity really seriously’.

‘It’s with such affection [for] these people and I hope this conversation highlights the fact that we really respect what they did, how they were as people and we just want the audience to know about it. And I hope that comes across.’

Who’s in the SAS: Rogue Heroes cast?

Sex Education star Swindells stars as David Stirling, with Skins actor O’Connell as Paddy Mayne and Game of Thrones’ Allen as Jock Lewes.

House of the Dragon actor Glynn-Carney appears as Mike Sadler, while The Crown star Dominic West portrays Lieutenant Colonel Wrangel Clarke.

House of the Dragon star Glynn-Carney plays the last surviving member of the original squad, Mike Sadler (Picture: BBC/Kudos/Rory Mulvey)

Sofia Boutella plays Eve, with Theo Barklem-Biggs as Reg Seekings, Paul Boche as Walter Essner and Moritz Jahn as Herbert Brückner.

Other members of the cast include Amir El-Masry, Corin Silva, Jacob Ifan, Dónal Finn, Jacob McCarthy, Michael Schaeffer, Miles Jupp, César Domboy, Adrian Lukis and Ramzan Miah.

SAS: Rogue Heroes premieres on Sunday at 9pm on BBC One and BBC iPlayer.

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The drama tells the tale of the SAS’s origins.