Why did I change some names and not others?
Actually, it is a difficult question to answer. If you are writing a book about the last great English castle on Dartmoor called Castle Drogo, it is a fact that it was designed by the famous architect, Edwin Lutyens, for Sir Julius Drewe and the gardens were to be designed by Gertrude Jekyll. I did not think I could change these names and similarly I could not change dates or places from World War I where battles took place. I also decided that if I was going to refer to Edwin Lutyens and Sir Julius Drewe, I ought to use the real names of their spouses. I thought I also had to keep Adrian's name, as there is a memorial room in Castle Drogo that is dedicated to him. Similarly, I decided to keep Krishnamurti's name as he is an historical figure in his own right.
Edwin and Emily Lutyens did not have a daughter called Celia. Their two eldest daughters were called Barbara (known as Barbie) and Ursula. I had discussed using Barbie's name as the lead character, but given the link that it has to a blonde doll, no one seemed to like it. I also worried that as the whole story relating to Celia was fictitious, including the relationship with Adrian, someone might object if I used a real person's name with another real person's name. Similarly, as the story relating to Christian Drewe was wholly fictitious I decided to use that name rather than Cedric Drewe (Sir Julius' third son).
I did not change the names of Mary Lutyens, Elisabeth Lutyens, Robert Lutyens or Basil Drewe because their roles in the novel are minor and each of them passed away many years ago.
Peter and Rose Hall are names that are wholly fictitious, as are the other minor characters that appear.