The National Gallery in London is alarmed about vandalism, but this was happening to pictures there over a hundred years ago

Before the First World War, the national Gallery was forced to take steps to protect its pictures from harm caused by political protestors

The National Gallery in London has started searching people who might be carrying liquids, in an attempt to prevent attacks by Just Stop Oil protestors. It will be recalled that on more than one occasion, this group has thrown soup over pictures in the gallery. This is not the first time that pictures in the National Gallery have been vandalised to draw attention to some political cause, of course. A very famous incident of this kind occurred in 1914, less than six months before the start of the First World War.