Longest-running Sci-Fi TV series with 800 episodes!!!
rom Tardis Data Core:
The show centres on a time traveller called "the Doctor", who comes from a race of beings known as Time Lords. He travels through space and time in a time machine he calls the TARDIS. This ship — which looks like a small, London police box on the outside — has nearly infinite dimensions on the inside. It has become such an iconic shape in British culture that it is currently the intellectual property of the BBC rather than its actual makers, the Metropolitan Police Service.
In order to accommodate cast changes, the narrative allows the Doctor to regenerate into an essentially new person on occasion. The cast is rounded out by one or more "companions", often females. On average, the main cast completely changes once every three or four years — a significant factor in the longevity of the programme.
It has had two — some argue three — major production periods. The original run of the programme was from 1963 to 1989, and is often called the "classic series" or "classic Doctor Who". A failed revival, in the form of a Universal-BBC co-production, came in 1996 — but the resulting one-off tele movie is often considered a part of the classic series. The current form of the programme — sometimes called the "new series" — has been produced by BBC Wales and aired on BBC One since 2005.
Though the classic series is fondly remembered by fans of a certain age, the new series has been far more consistently popular with the British public, and is usually the highest-rated scripted drama — outside of perennially popular soap operas — in the weeks that it is on the air.