Cannon-pocked buildings, rubble-strewn streets and corpses half-buried in the ruins of a fort: these were the first photographic scenes of the devastation of war fed back to Victorian Britain from the front lines of the Indian Mutiny and the Second China War.

The man behind the lens was Felice Beato, a young Corfiot photographer intent on creating a name for himself. Having gone to India to capture the aftermath of the Indian Mutiny, he travelled to the palace of Secundra Bagh in Lucknow, where several thousand rebels had been slaughtered in some of the fiercest fighting with British and East India Company regiments. With an eye for the dramatic, he rearranged the skeletal remains of the Mutineers in a gruesome composition in front of the palace.

His career soon took him to China in 1860, where he photographed Taku Fort outside Peking after fighting had ceased. While British casualties had already been removed from the scene, Beato demanded that no one should disturb the “beautiful bodies” of the enemy casualties.

He also recorded the emperor’s Summer Palace, which had been looted by Anglo-French forces. He later photographed the same sweep of serene pleasure grounds — this time the palace had been razed to the ground.

The photographs, when they appeared in Britain, established his reputation as a war photographer and were bound into books.

The National Army Museum, in London, is devoting its White Space Gallery to a new exhibition of the work of four pioneering war photographers: Felice Beato, Roger Fenton, James Robertson and Josh McCosh.

Several years earlier Roger Fenton was commissioned as the first official military photographer to go to the Crimea. He was sent out by Prince Albert, and it was hoped that his photographs would help to counter the increasing hostility to the war in Britain.

The Times special correspondent William Howard Russell, whose picture Fenton took, was among those who stirred public outrage about soldiers’ living conditions in the Crimea. “The commonest accessories of a hospital are wanting; there is not the least attention paid to decency or cleanliness . . . and, for all I can observe, these men die without the least effort being made to save them,” he wrote.

Fenton’s photographs of soldiers in theatre were the first of their kind. However, they contained no dead bodies but, instead, soldiers posing in peaceful scenes. One, L’Entente Cordiale, shows a group of French and British soldiers relaxing with a drink; in another the soldiers show off their newly arrived sheepskins — in spring.

Fenton’s most celebrated image is The Valley of the Shadow of Death. The desolate valley, littered with round shot and shell, was the scene of the disastrous charge of the Light Brigade at the Battle of Balaclava.

Although he was not immediately endangered by the fighting, Fenton was at the same risk of disease as the soldiers. Indeed, on different occasions he suffered from both broken ribs and cholera. He organised his own transport through the Crimea, travelling with all his equipment in an old horse-drawn wine merchant’s van — an easy target for enemy attack. Inside was a darkroom and space for him to sleep. In letters home he often grumbled about the heat, flies and dust that plagued his equipment.

The earliest works on display are those of Josh McKosh, whose photographs were taken durning the Sikh wars in 1848. The misty portraits are a reminder of just how pioneering the photographers and their equipment were. In his memoirs McKosh wrote humbly that while his works were of no great merit, they may one day be of historical significance.

First Shots: Early War Photography 1848-1860 is running in the White Space Gallery, the National Army Museum, London SW3 from today until January 10; 020 7881 2455; national-army-museum.ac.uk