For six decades, the Doctor has been zipping through time and space in the TARDIS, but this iconic character is equaled only by their greatest foes. While Doctor Who has plenty of iconic monsters from the Cybermen to the Sea Devils, none of the villains are nearly as popular as the Daleks. With a single eyestalk, a cannon and a plunger, the armored Daleks originally out-shined the show's hero. The first serial to introduce them -- known by many names but most simply "The Daleks" -- made the creatures an overnight phenomenon in Britan and everywhere else Doctor Who was seen.
Source：https://www.cbr.com/doctor-who-terry-nation-daleks-explained/
