Image copyright IWM/Richard Ash Image caption The exhibition features a reconstruction of the 80s Greenham Common women's peace camp

The idea of Britain opening an Imperial War Museum dates from 1917. An exhibition to mark the centenary takes the IWM in London a long way from tanks and battleships.

People Power: Fighting for Peace looks at how the British have protested against war. It covers everything from posters and poetry to street-demonstrations. But the show also asks if the era of mass protest is coming to a close.

There has been no shortage of TV programmes and exhibitions based on the centenary of the World War One. But Matt Brosnan, curator of the IWM exhibition People Power, says he didn't hesitate to start the story of anti-war protest there.

"Protest is part of the hidden history of the 1914-18 war," he says. "People have heard of conscientious objectors but don't know about groups like the No Conscription Fellowship, which was quite significant. And there's a lot to say about a pacifist group like the Quakers.

Image copyright IWM/Paul Nash Image caption Paul Nash's Wire was painted in 1918, the year that World War One ended

"Then we move on to the lead-up to the Second World War, and then to the 1950s and real anxiety about the H-bomb. Finally we come more up to date with protests about Iraq. The four different eras have differences but there are also strands which unite them. We try to surprise people too."

Brosnan says visitors won't expect to find a picture of AA Milne, who created Winnie the Pooh. "But he was a pacifist, who in 1934 published a book called Peace with Honour. We look at how by the end of the decade the rise of Hitler made that position more difficult."

The 1950s brought mass protests against nuclear weapons. "We're delighted to have some of the original designs by Gerald Holtom for possibly the best-known peace symbol of them all, designed for the first Aldermaston anti-nuclear march in 1958," says Brosnan.

Britain had little experience of political protest on that scale and you see an echo of the Ban the Bomb marches in protests after Britain sent troops to Iraq in 2003.

This photo-montage from 2005, the work of Peter Kennard and Cat Picton-Phillipps - of then Prime Minister Tony Blair and an explosion - became one of the best-known images reacting to the Iraq War.

Image copyright Peter Kennard/Cat Picton-Phillipps

But Brosnan believes we're at an interesting point in the history of mass anti-war protest.

"Even since the Iraq War we've become a much more online society.

"It's easy for people now to register protest by just clicking on a website. That may get headlines but it may also be getting harder to get boots on the ground.

"Possibly things like the big CND marches of the 50s and 60s and the Greenham Common protest of the 1980s would be harder to organise now."

During the Iraq War there were several variations on the "blood splat" poster produced by well-known artist David Gentleman.

Image copyright David Gentleman

The show also exhibits for the first time a manuscript by World War One poet Siegfried Sassoon of his well-known poem The General.

In print its final line has always been: "But he did for them both by his plan of attack." In the manuscript on display the line becomes the even angrier "murdered them both".

Image copyright Getty Images Image caption War poet Siegfried Sassoon also features in the exhibition

There was a women's anti-nuclear peace camp outside the Greenham Common airbase in Berkshire from 1981: it remained for almost 20 years. One of the banners, made by Thalia Campbell, was widely seen at the time.

Image copyright Thalia Campbell Image caption Thalia Campbell made a banner depicting the unity of the women at Greenham Common

In 1981 Peter Kennard made the ironic comment about the impact of nuclear war, with an image of a skeleton reading Britain's official government booklet, Protect and Survive, on what to do in the event of an attack.

Image copyright IWM/Peter Kennard Image caption Peter Kennard parodied the official nuclear survival guide

Gerald Holtom's famous peace symbol was created in 1958 for a protest march. It became closely associated with the Campaign for Nuclear Disarmament but has also been used more widely around the world.

Image copyright IWM/Gerald Holtom

People Power: Fighting for Peace is on at London's Imperial War Museum from 23 March until 28 August.