Second Doctor

The Second Doctor is an incarnation of the Doctor, the protagonist of the British science fiction television series Doctor Who. He was portrayed by actor Patrick Troughton. Within the series' narrative, the Doctor is a centuries-old alienTime Lord from the planet Gallifrey who travels in time and space in the TARDIS, frequently with companions. At the end of life, the Doctor regenerates; as a result, the physical appearance and personality of the Doctor changes. The introduction of the Second Doctor was the first to portray the concept of regeneration (a concept not yet fully realised, instead called "renewal") and was a significant moment in the evolution of the series, eventually becoming a critical element for its longevity.

Preceded in regeneration by the First Doctor (William Hartnell), he is followed by the Third Doctor (Jon Pertwee). Troughton's Doctor was an outwardly scruffy, light hearted and bumbling tramp, a portrayal that was called the "cosmic hobo". The Second possessed a comical demeanor that he used to manipulate his enemies. His original companions were Ben Jackson and Polly Wright (Michael Craze and Anneke Wills), a sophisticated socialite and a working-class sailor, who were companions of his previous incarnation. They were later joined by Jamie McCrimmon (Frazer Hines), an 18th century Scotsman, who became the Second Doctor's longest-serving companion. Following Ben and Polly's departures, the Doctor and Jamie were joined by the Victorian orphan Victoria Waterfield (Deborah Watling) and 21st century astrophysicist Zoe Heriot (Wendy Padbury). The Second Doctor would be colloquially dubbed "the monster Doctor" for the prevalence of new and returning monsters, an encompassing term for the series' antagonists, in his episodes.

The Second Doctor concluded his tenure by the end of the 1969 serial The War Games, where he is forced to regenerate by the Time Lords, with his future incarnation banished to Earth as further punishment, although the existence of a "Season 6B" suggesting the Second Doctor continued to live past the finale of The War Games has remained a popular topic within Doctor Whoexpanded universe media. After his departure, Troughton reprised the role for multiple guest appearances in later episodes of the series, beginning with The Three Doctors (1973). He made his last appearance in The Two Doctors (1985) alongside the Sixth Doctor (Colin Baker), with Troughton dying two years later. Since then, the Second Doctor has been featured in video games, novels, and via archival footage in the revival series.

Despite contemporary reception being mixed towards the Second Doctor, the character would undergo a critical reevaluation that has proven largely favourable. The Second has frequently been cited as a significant influence on later actors that went on to portray the Doctor, being referred to by several of them as their personal favourite. The Second Doctor's era was victim to wiping, a process where tapes of older episodes would be erased for newer material to be recorded over, which was common practice at the BBC between the 1950s to the latter half of the 1970s. As a result, nearly half of the episodes featuring the Second Doctor have been lost.