River Song is a fictional character created by Steven Moffat and played by Alex Kingston in the British science-fiction series Doctor Who. River Song was introduced to the series as an experienced future companion of series protagonist the Doctor, an alien Time Lord who travels through time in his TARDIS. Because River Song is a time traveller herself, her adventures with the Doctor occur out of synchronisation; their first meeting (from the audience's perspective) is his first and apparently her last. 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.