UNIT went on to feature in many Third Doctor stories, as the Doctor is shown being exiled to Earth in "Spearhead from Space" (1970), and becomes UNIT's Scientific Advisor following the Auton attack. The Doctor would maintain this post in subsequent incarnations. UNIT is a large organisation and many personnel have featured in "Doctor Who" over the years. Some lead, supporting and recurring characters have worked for or have been affiliated with the organisation. The most notable personnel include The Brigadier, Sergeant Benton, Mike Yates, Petronella Osgood, Kate Stewart, and Martha Jones.