Who is Kate Stewart and actor Jemma Redgrave in Doctor Who?

That episode introduced Ncuti Gatwa's Doctor for the first time, but this instalment sees Kate solely meeting with Millie Gibson's Ruby Sunday, in a crucial scenes midway through the episode.

We already knew that Kate would return this season, and are expecting her to pop up on at least one more occasion, as showrunner Russell T Davies has confirmed that she will be back in action for the two-part finale, The Legend of Ruby Sunday and Empire of Death.

Davies also recently opened up about what role UNIT will play this season, saying he'd like the organisation to return "every year" - but just who is Kate and who is the actress who plays her, Jemma Redgrave? Here's everything you need to know.

Who is Kate Stewart in Doctor Who?

Kate Stewart, born Katherine Lethbridge-Stewart, is the Chief Scientific Officer and Head of UNIT and an ally of The Doctor.

The character is also the daughter of the long-running recurring ally to The Doctor, Brigadier Lethbridge Stewart (Nicholas Courtney), a much-loved character from the classic series.

Kate made her debut in the 2012 story The Power of Three, opposite Matt Smith's Eleventh Doctor.

The character returned in the 50th anniversary special The Day of the Doctor in 2013 before becoming a recurring character in the era of the Twelfth Doctor (Peter Capaldi), appearing in the episodes Death in Heaven, The Magician's Apprentice, The Zygon Invasion, and The Zygon Inversion.

Stewart made a comeback as part of the Flux season in 2021 in the episodes Survivors of the Flux and The Vanquishers, opposite Jodie Whittaker's Thirteenth Doctor.

The following year, Stewart appeared as an ally of The Doctor in the centenary special The Power of the Doctor, which also served as the final episode of the Thirteenth Doctor.

The character also returned to aid the Fourteenth Doctor in the 60th anniversary special The Giggle and will be a recurring character in the first season to star Ncuti Gatwa as the Fifteenth Doctor.

She appears in 73 Yards, as she attempts to help Ruby by getting hold of the mysterious woman who has been following her around, always 73 yards away.

While meeting Ruby at a cafe, Kate and her UNIT troops attempt to take the woman into custody but fail, and, as has happened each time before, the woman causes Kate and UNIT to abandon Ruby.

Recently speaking about the return of UNIT this season, Davies told Doctor Who Magazine: "With any luck, we’ll return to UNIT HQ every year, in different ways. It’s particularly lovely to see the Doctor greet Mel again, because she was holding his hand when he bi-generated – she was the first person ever to touch the new Doctor – so there’s a real joy in seeing them give each other a great big hug."

He added: "Kate and the Doctor have a lovely conversation about Brigadier Lethbridge Stewart [Kate’s late father, who led UNIT during the Second, Third and Fourth Doctors’ eras], where he’s remembered. Jemma, of course, has been such a constant…

"And the new parts we’re building up… discoveries like Alexander Devrient, who gives such a subtle and detailed performance. It’s a joy to give him more and more to do. And Ruth Madeley is still part of the gang. I can reveal that she’ll be back next year. And Lenny has become family – he’ll be back at some point too."

Who is Doctor Who actor Jemma Redgrave?

Jemma Redgrave is a British actress known for her television and stage roles.

Redgrave is also a member of the Redgrave acting dynasty as the daughter of actor Corin Redgrave and his first wife Deirdre Hamilton-Hill, a former fashion model.

Jemma is the granddaughter of Sir Michael Redgrave and Rachel Kempson, meaning she is also the niece of actresses Vanessa Redgrave and Lynn Redgrave.

Through these relationships, Redgrave is also the cousin of Joely Richardson, Carlo Nero and the late Natasha Richardson.

Outside of her role as Kate Stewart, Jemma Redgrave is known for her parts as Major Berenice Wolfe in Holby City, and Amelia in Grantchester, as well as parts in Bramwell, Cold Blood, Judge John Deed, and Waking the Dead.

Doctor Who continues on Saturday 1st June on BBC iPlayer and BBC One. Previous seasons are available to stream on BBC iPlayer with episodes of the classic series also available on BritBox – you can sign up for a 7-day free trial here.

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