Polly and Ben are the second and last companion couple in Dr Who, the first being Ian and Barbara. They don't begin as a couple as did Ian and Barbara, they met in the second episode of "The War Machines" and hit it off. After a few adventures with the Doctor, one of the usual TARDIS navigational problems put them back in London in 1966 (The Faceless Ones), at pretty much the time they had left so they decided to stay.
Polly is played by Anneke Wills
Ben is played by Michael Craze.