Chichester was a city located in England.
At the time of the Wenley Moor Silurian incident, Alistair Gordon Lethbridge-Stewart realised that he was an inadequate father to his daughter, Kate. The secretive nature of his work with UNIT prevented him from being consistently present in her life. His long absences from home caused his wife Fiona to leave him. Alistair guessed that she and Kate went off to at least initially live somewhere close to Chichester, the home of Kate's maternal grandparents. (PROSE: The Scales of Injustice [+]Gary Russell, Virgin Missing Adventures (Virgin Books, 1996).)