The 83rd Doctor was played by renowned sitcom actor Derek Deadman. He appeared in seasons 340-343 of the long-running British SF series, "Doctor Who", which aired between the years 2336 and 2339 on BBC 1.
He was accompanied by his stunning blonde sidekick Millicent.
Under the auspices of a radical new Producer, Geoff Cambridge-Smythe (who was more used to producing light entertainment programs as opposed to SF drama), the show took a distinct turn for the worse, causing many fans to declare that the series was "not as good as it had been in the past" and "ruined forever".
This troubled era caused many Whovians to rename the series "Doctor Hasn't A Clue".
Equipped (as usual) with his trusty Sonic Hammer (TM), the Doctor was an engaging figure, but alas, almost totally useless and utterly incompetent.
This incarnation of the Doctor would often fail to spot things which were right in front of his eyes and during his four years in the role he completely failed to thwart any alien invasions whatsoever.
In fact, the 83rd Doctor's entire tenure saw him standing around making wisecracks and waiting for the live studio audiences to respond to jokey punchlines whilst the aliens were able to implement their plans almost completely unmolested.
One episode in particular consisted of a single monologue of topical asides by The Doctor, and the following episode saw him interviewing guests in a studio on Rigel VII.
Within the series' mythology, this inactivity on the Doctor's part led to almost total universal domination by the Daleks, who actually awarded him a medal for services to the Dalek Empire and regularly invited him to parties. Indeed, season 343, Deadman's last in the role, saw the Doctor ditch the TARDIS completely and move into a Seattle apartment which he shared with a Dalek, a Cybermat and a raggedy old sofa - with hilarious consequences.
Deadman and Cambridge-Smythe were assassinated in December 2339 by a cadre of aggrieved Doctor Who fans, leading to a reinvigorated series two years later.