One death in the First World War I shall now always remember. It is only one of the many remembered by the National Portrait Gallery’s exhibition, “The Great War in Portraits” (until 15 June) and commemorated at north London’s Jewish Museum, in its “For King and Country” exhibition (until 10 August).This death is an anonymous one, no face is even seen, shown in a remarkable film of the Battle of the Somme at the first exhibition, and commissioned by the Ministry of Propaganda. Men come up the line and crouch below the trench parapets. At the signal they scramble up and go over the top. Except for one. He slips and slides back to a waiting position, never having got over the parapet. We wait – he’s slipped: surely, he is about to move again.