Lost in time and space

Between about 1964 and 1973, large amounts of older material stored in the BBC's various video tape and film libraries were either destroyed,wiped or suffered from poor storage which led to severe deterioration from broadcast quality. This included many old episodes of Doctor Who, mostly stories featuring the first two Doctors: William Hartnell & Patrick Troughton. Following consolidations and recoveries the archives are complete from the programme's move to colour television (starting from Jon Pertwee's time as the Doctor), although a few Pertwee episodes have required substantial restoration; a handful have been recovered only as black-and-white films, and several survive in colour only as NTSC copies recovered from North America