It is no longer fashionable to admire Henry Moore, an artist who, in the Betjeman mould, was once a national institution, but whose later huge and ubiquitous public sculptures of reclining figures became dully repetitive and uninspired.

Disregarding prevailing modes, however, a series of recent exhibitions have invested in a programme of, at least partial, rehabilitation. The last notable exhibition to successfully revive interest was at the Dulwich Picture Gallery a couple of years ago.

Concentrating on his maquettes and his well-known drawings of Londoners sheltering on the Underground during the Blitz, we were reminded once again just why Moore's work was once both critically acclaimed and popular.

Now we have the Imperial War Museum's current exhibition concentrating on the years 1938 to 1954. This takes into account his artistic responses to the Spanish Civil War, his years as an official war artist and the profound influence both conflicts had on his work.

For instance, a haunting 1939 lithograph of the head of a prisoner of war during the Spanish conflict shows a figure confined by a series of external elements. As we see here, it was a work that led to an important series of sculptures of forms within forms.

The most memorable part of this exhibition, however, remains Moore's series of war drawings of the Underground. His shrouded, ghost-like figures, huddled or asleep at the foot of black, gaping tunnels (pictured), remain as vivid and as powerfully poignant as ever.

Until Feb 2007, Imperial War Museum, Lambeth Road SE1, daily 10am to 6pm, £7, free to £5 concs. Tel: 020 7416 5000. Tube: Lambeth North/Elephant & Castle