The Daleks are a race of alien mutants who live inside heavily armed travel machines. They are militaristic, xenophobic and highly aggressive and are dedicated to universal conquest and the destruction of all non Dalek life. They have been frequently opposed by the Time Lord known only as The Doctor.
Several varying accounts exist as to the Daleks' origins. According to the earliest, recorded in The Dalek Chronicles, the mutants were created by the humanoid Dalek scientist Yarvelling at the behest of Minister Zolfian as the only viable means of allowing his race to survive the radioactive fallout created by the accidenta detonation of a neutron bomb on their home planet of Skaro. This account states that the mutant Daleks superseded their humanoid forebears and, ruled by a golden Emperor, expanded out into the universe after a near civil war caused by the superintelligent Dalek Zeg. They later encountered resistance from the likes of the Mechonoids and the robot 2K, created by the Zerovians.
A later account, however, states that the Daleks were created by the Kaled scientist Davros as the means of winning a war between his race and the Thals who shared their planet. This account is now regarded as definitive, though it is possible the Dalek Chronicles are set in an alternate timeline.
A third, largely discounted account, states that the Daleks are the ultimate descendants of humanity.