Doctor Who is a British sci-fi TV series based on the adventures of Time Lord - Dr Who - who travels through time in the TARDIS. The Doctor has been played by 11 actors, including John Pertwee, Sylvester McCoy, Tom Baker, Christopher Eccleston and David Tenant, and is currently played by Matt Smith. During his time and space travelling, the Doctor encounters many enemies including The Cybermen, Davros, and the Weeping Angels. The most famous adversaries are The Daleks, whose single aim is to "Extermin-ate!" all inferior beings. The series is just as popular today as when it first started back in 1963, and holds the Guinness world Record for the Longest Running Science-Fiction Television Series.