Played Rory Williams (2010-2012)
Initially introduced as Amy Pond’s awkward and gawky fiancé, the brilliant Rory Williams became a beloved companion in his own right, with both his and Amy’s relationship fiercely tested throughout their two years on the show.
After exiting the series in 2012, Arthur Darvill has since gone on to star in huge ITV hit Broadchurch, playing the ever-so-slightly creepy Reverend Paul Coates alongside Tenth Doctor, David Tennant.
Darvill, 36, is now playing a superhero in his own right, starring as the devilish Rip Hunter on American TV series Legends of Tomorrow.
Played River Song (2008-2015)
After a cameo appearance in 2008 episode Silence in the Library, River Song became an established companion to Matt Smith’s Doctor, after it was revealed that she was actually Melody Pond – Amy Pond and Rory Williams’s daughter.
As a time traveller herself, River and the Doctor’s appearances are not in sync, with River’s death coming when she is first introduced in the series. She is last seen on screen in the 2015 Christmas episode The Husbands of River Song, where the pair – who previously got married in 2011 episode, The Wedding of River Song – spend their last night together.
Since her appearance in Doctor Who, Alex Kingson has gone on to star as Dinah Drake Lance in Arrow until 2016, alongside fellow Who actor John Barrowman.
She also played Miranda Pond from 2009-10 in Law & Order: Special Victim Unit, and Naomi Shropshire in the Netflix reboot of Gilmore Girls.
The Cry airs on Sundays at 9pm on BBC1