Richard Knight, military historian, with Edith Cavell's tombstone at Norwich Cathedral. - Credit: Danielle Booden A military historian is calling for greater protection of the gravestone for First World War heroine Edith Cavell after finding it covered in muddy footprints. Richard Knight, 57, from Marsham, an experienced guide of First World War battlefield visits for school students in France and Belgium for Anglia Tours, said was shocked to see people had been disrespectful to the nurse's memory. Edith Cavell's tombstone on Life's Green on the grounds of Norwich Cathedral. - Credit: Danielle Booden The memorial next to Norwich Cathedral replaced the original gravestone on Life's Green, which was a cross and was surrounded by a garden, in 2015 on the centenary of nurse Cavell's death.