The world’s largest memorial is about to get a little bigger, as it comes to Britain for the first time. It began life in 1992, when German artist Gunter Demnig laid the first “ Stolperstein ” – or stumbling stone – in Cologne, Germany. Since then, more than 75,000 memorials, each the size of a square cobble stone, have been installed in more than 20 countries. Britain is now to be added to that growing list as a 10 x 10cm brass plate is unveiled in Golden Square, in central London. On it will be engraved the name of Ada...