Who has been your biggest influence?
Many of my own teachers: Mrs Penny Bazire, headmistress of my junior school, had confidence in me and all her pupils; Miss Launder, my biology teacher at my senior school, was terrifying and never let us get away with anything; John Barker, my PGCE tutor, approached every lesson with the most wonderful sense of humour.
What is your career high so far?
Being appointed to each of my two headships. The first was at Woldingham School in Surrey, a Catholic girls' boarding school. The second was my current appointment, at the City of London School for Girls. It is a particularly wonderful school because of its location and the fact that we are able to provide financial support for about 28 per cent of the pupils.
What was your worst moment in teaching?
Having to suspend a girl during my first weekend as a head. She had an acute eating problem and had been stealing from her friends and behaving erratically in a way that could endanger herself and others. When I told her and her mother that I would not have her back in school until she had gained weight, she looked at me with loathing. Some years later she returned to the school and thanked me: she would not have recovered had I not acted as I did.
What is the best piece of advice you have been given?
A fellow head at a conference suggested that there are four key attributes that you need in order to be a good head: courage, compassion, humility and a sense of humour.
What is the most outrageous thing a colleague has done?
I am very disappointed by petty staffroom politics, which can undermine the morale of teachers. I was particularly disappointed when I found out the sorts of things that some of the teachers say to their classes about their colleagues. One of my pupils was shocked that teachers could behave in a way that she felt was no better than teenagers.
What would you be if you hadn't become a teacher?
Prior to becoming a teacher I worked in corporate and financial PR, but I have always felt that if I had a third career it would be medical or healthcare related.
What is the worst excuse you have ever heard?
Parents can make some shabby excuses as to why they want to extract their children during term time for holidays.
Diana Vernon has been headmistress at City of London School for Girls since 2007.