When Stella Flatten bought her terrace house in south Berlin’s Fliegerviertel (aviation district) several years ago, a condition set by the seller was that she would research the history of its first owner. “It was a big responsibility and whilst part of me wondered why the previous owner hadn’t done it, I willingly embraced the task,” she said. In between sanding down the original floorboards and uncovering the first layers of paint used to decorate the walls, she has been painstakingly piecing together the life of Gertrud Rothgiesser, a leading Berlin paediatrician and campaigner for better living conditions for city...