Reading these reports of what has been happening in some co-educational public schools, it’s clear that the trend began way back at the end of the 1960s. Back then, I was a guinea pig – and both I and the system have a lot to answer for.

John Dancy, the headmaster of Marlborough College, known as a ‘progressive headmaster’, thought it was wrong that his daughter could not benefit from the education enjoyed by the boys in his public school – so he proposed as an experiment that his daughter and daughters of other masters should be allowed to join the school...