River Song is a fictional character created by Steven Moffat and played by Alex Kingston in the British science-fiction series Doctor Who.

Kingston plays her in 15 episodes, as River becomes a companion, romantic interest and eventual wife of the Doctor in his eleventh incarnation portrayed by Matt Smith.

River Song was created by Doctor Who writer Steven Moffat for the show's fourth series in 2008, under the tenure of then executive producer Russell T Davies.

When Moffat took over Davies' duties as executive producer, he began expanding on the character's background, depicting adventures earlier in River's timeline, upgrading Alex Kingston from a guest star to a recurring actor in the series.

River, who is a professor of archaeology and carries a TARDIS-colour/pattern diary of her adventures, is able to convince the Doctor of his future trust in her by whispering his real name into his ear, which he explains he would only divulge under rare circumstances.

In the two-parter "The Time of Angels"/"Flesh and Stone", which takes place prior to River becoming a professor, she encounters the Eleventh Doctor (Matt Smith), again having more history with him than he with her.

In the 2011 series opener "The Impossible Astronaut"/"Day of the Moon", River, along with Amy and her husband Rory (Arthur Darvill), is contacted by a future version of the Doctor to meet up in the United States.

As they enjoy a lakeside picnic, this future Doctor is killed by an assailant in a space suit, and the trio give him a Viking funeral, in Lake Silencio.

At some point after regenerating in New York, Melody becomes Rory and Amy's childhood friend Mels (Maya Glace-Green) and grew up with them, and enlightened them to their romantic feelings for each other and ensuring her own existence.

When adult Mels (Nina Toussaint-White) is shot, and regenerates into her next incarnation (Alex Kingston), she proceeds to do what she was created for: assassinate the Doctor.

River appears again in the fifth episode of the seventh series, "The Angels Take Manhattan" (2012), where she encounters the Doctor and her parents, in 1930s New York City.

River is also referenced in the episode "Extremis", and it is revealed that she ordered her employee Nardole (Matt Lucas) to keep an eye on the Doctor for her in the event of her death.

The series was announced on 27th June 2015, along with the news that Kingston would make a guest appearance as River in volume two of the ongoing The Eighth Doctor Adventures saga, Doom Coalition.

Kingston would later join the cast of The Tenth Doctor Adventures for the concluding part of its Dalek Universe saga, while Tennant would make an uncredited cameo in volume eight of Diary.

[11] Marking International Women's Day 2019, River appears in an episode of The Eighth of March where she teams up with former companion Leela (Louise Jameson).

[14] For the role of River Song, whom executive producer Russell T Davies described as "sort of the Doctor's wife", the production sought to cast Kate Winslet.

[23] For the filming of the sixth series, Kingston was aware of River Song's relationship to Amy and Rory, while the other cast only found out upon reading of the mid-season cliffhanger script for "A Good Man Goes to War".

"[26] Kingston has also praised the way the love story between River and the Doctor has been deftly handled, stating that "I'm not sure you'd get that kind of dynamic in America".

For Kingston, the physical age difference between herself and Matt Smith adds to the success of the pairing, whilst she feels that viewers have responded warmly to the notion of an action hero in her 40s.

[28] River's characterisation has invited parallels with that of Jack Harkness (John Barrowman), a companion of the Ninth and Tenth Doctors introduced by Steven Moffat in 2005.

[29] Upon River's return in series five, Lyle Masaki of AfterElton felt that viewers had the chance to see the character "do her best to channel Captain Jack" by capturing the same "'charming rogue' vibe".

Heather Hogan, a senior editor of AfterEllen felt that Moffat's ability to create "fascinating, complicated characters like... River Song" is a direct consequence of him abiding by "Captain Jack's label-eschewing motto": "You people and your quaint little categories".

[31] James Cornish of WhatCulture subsequently cited River's characterisation in a rebuke against claims of misogyny and homophobia in Moffat's writing.

Club compared the Doctor and River's romantic storyline to The Curious Case of Benjamin Button, based on the F. Scott Fitzgerald short story, "if a bit more elegantly, for my money—it echoes the plight of anyone who's watched a loved one fade into the shadowlands of dementia.

[37] Neela Debnath of The Independent praised Nina Toussaint-White in her role as Mels, saying she was "every bit as sassy and vivacious as her later incarnation... it was a shame that she regenerated so early on because she brought a different energy to the character".

[38] However, Neil McCormick in The Daily Telegraph thought that her sudden introduction as Rory and Amy's childhood friend showed that Moffat was making it up as he went along.

[39] Charlie Jane Anders of io9 felt that River Song was at her "high point" in some of the early Matt Smith episodes, where she was "generally badass and mysterious".

[40] Whilst critical of the typical characterisation of British female science fiction characters, The Guardian's Krystina Nellis singles out River Song alongside Torchwood's Gwen Cooper (Eve Myles) as positive depictions of strong female characters, stating: "It'd be difficult to find two superwomen in less need of a man to save them.

"[41] For her role as River Song in the 2011 series of Doctor Who, Alex Kingston won the Best Actress prize at the 2012 SFX magazine Awards.

[42] In a 2012 poll conducted by SFX magazine to find the 100 sexiest female characters in science fiction and fantasy, River was voted number 22.