Doctor Who's War of the Sontarans featured nod to a classic Jon Pertwee serial

Aired as the opening story to Doctor Who's 11th season between 15th December 1973 and 5th January 1974, The Time Warrior was written by Robert Holmes and saw the Third Doctor (Jon Pertwee) and new companion Sarah Jane Smith (Elisabeth Sladen) travel back in time to the Middle Ages.

Back in 13th century England, the pair faced off against Linx (Kevin Lindsay), a Sontaran who'd decided to claim Earth for his empire after crash-landing on the planet. The alien was finally felled by – you guessed it – a blow to his probic vent, with the archer Hal (Jeremy Bulloch) firing an arrow straight at Linx's weak spot.

Following the story's broadcast, the Sontarans went on to become one of Doctor Who's most popular recurring foes, later taking on the Fourth Doctor (Tom Baker) in 1975's The Sontaran Experiment, invading Gallifrey in 1978's The Invasion of Time, taking on two versions of their Time Lord nemesis in 1985's The Two Doctors, and making their new Who debut in 2008's The Sontaran Stratagem/The Poison Sky.

But the OG Sontaran, Linx, hasn't been forgotten – and is directly referenced in Flux: Chapter 2 – War of the Sontarans, some 48 years on from the character's sole television appearance.

As the Doctor (Jodie Whittaker) takes a Sontaran commander (Jonathan Watson) to task for invading Earth and changing the planet's history to boot – with the Sontarans having replaced Russia in opposing the United Kingdom in the Crimean War – said Sontaran reminds her that his race have a long and storied humanity with humanity, going all the way back to Linx's arrival.

"This planet has defied us ever since the great Commander Linx first staked his claim on the ground of its feeble soil," he growls.

It's a fleeting reference but a pleasing one for long-time Doctor Who fans, not to mention a way of paying tribute to late Linx actor Kevin Lindsay.

Born in Bendigo, Victoria in Australia, Lindsay came to Britain in 1959 and took on a series of roles in classic Doctor Who – including that of Cho-Je in Jon Pertwee's final story, 1974's Planet of the Spiders. But it was for playing Linx – and later Sontaran Field Major Styre in The Sontaran Experiment – that he's best remembered.

Lindsay passed away in 1975, nine days after his 51st birthday, but his original portrayal of Linx remains the definitive Sontaran performance aped by all who've followed in his footsteps – from the harsh snarl of the voice to the creatures' habit of sticking their tongue out.

With Doctor Who: Flux telling one serialised story over six weeks, it remains to be seen if upcoming instalments will offer up any more linx (sorry!) to the show's past.

Listen to the new episode of the Radio Times Doctor Who podcast:

Read more about Doctor Who:

• Doctor Who’s latest episode adds another big mystery to the pile of big mysteries
• Why does Doctor Who: Flux keep ruining its own cliffhangers?
• Doctor Who: Flux reveals title of episode 4 featuring Weeping Angels
• Should Doctor Who's Mandip Gill and John Bishop stay on after Jodie Whittaker leaves?

Doctor Who airs on BBC One on Sundays. For more, check out our dedicated Sci-Fi page or our full TV Guide.