Genesis of the Daleks

Genesis of the Daleks was the fourth serial of season 12 of Doctor Who. It introduced Davros, creator of the Daleks, and showed the story of their origins. Davros later played a prominent role in every following Dalek serial up to Remembrance of the Daleks in 1988.

Genesis of the Daleks is also notable for being the only time in the classic television series that the TARDIS does not appear whatsoever for two consecutive serials.

Also notable is the fact that this is one of the only two Dalek serials in all seven years of Tom Baker's run on the show, the other being 1979's Destiny of the Daleks. This became the start of a practice throughout the classic series where most recurring enemies would see a significant reduction in the amount of encounters between them and the Doctor; the Daleks, to name an example, only starred in one televised serial during each succeeding Doctor's tenure for the remainder of the 1963-1989 run.

In a 1998 poll conducted by Doctor Who Magazine, Genesis of the Daleks was praised by fans as their favourite Doctor Whostory of all time. (DWM 265)

Synopsis
Intercepted while travelling between Earth and the Ark, the Fourth Doctor and his companions are transported to the planet Skaro, thousands of years in the past, on a mission for the Time Lords — to prevent the creation of the Daleks.