‘What do you do?’ a midwife asked as she helped me to the bathroom. We were in the postnatal ward for people who have had a bad time of it. ‘I’m a historian of ... all this,’ I answered, and gestured vaguely at the wreckage of the ward. Two and a half years on, I can say, expertly, continently: between the 16th and the 18th century, midwifery was transformed.