Don McCullin, who has a fair claim to the title of the UK’s greatest living photographer, was born in 1935 in Finsbury Park – a bloody tough area of London before the war, and even more so after, when much of it had been bombed flat. The first photograph McCullin was paid for, in 1958, and almost the first exhibit in the Tate’s monumental and unmissable retrospective of his work, was of a neighbourhood gang, peacocking within the exposed rooms of a bombed-out house. This particular gang had been implicated in the stabbing of a local bobby, which gives you two of the most significant themes in McCullin’s photography right there: first, that the more things change, the more they stay the same; and second, that his photographs so often deal with those in uniform confronted by those who are not. Another early shot shows a woman-protestor in late middle-age being carried away from one of the Aldermaston marches by two policeman, both young enough to be her sons, with all three protagonists in the scene registering the ridiculousness of it; and so is the photographer. McCullin’s upbringing was also bloody tough, which could affect you in one of two ways: it could mean you joined one of those knifed-up gangs (in the Finsbury Park of the 1950s, white), or it could foster in you a sense of humour, and of empathy and respect for those around you, whoever they may be. McCullin operates ‘not as a photographer but as a human being,’ he tells us, in the praiseworthily intelligent wall-text to the show. He calls his task ‘being there’, and there is much in his work to make you think of Henri Cartier-Bresson and Cartier-Bresson’s maxim of ‘the decisive moment.’ But McCullin leaves his subjects with a dignity even in death that is, perhaps, unique to him.

McCullin credits his experiences photographing the Turkish invasion of Cyprus with the development of his sense of empathy with his subjects, but really it’s there from the first, from his early morning image of sheep being driven down the Caledonian Road to a slaughterhouse (McCullin is a terrific photographer of animals, too) to his record of the Berlin Wall going up – the workers toiling away, digging its foundations while being bossed by soldiers in greatcoats (what resonance that combination in that place has, in particular), and the weight of sorrow on the faces of women in the crowd in West Berlin, watching the Wall rise. It’s there too in his photographs of the conflict in the Congo in the early 1960s, especially a sequence of four teenage boys, one already wounded and bandaged, being tormented by soldiers as a prelude to being shot. Everything in the bandaged boy’s face speaks of his determination to rise above the soldier’s behavior.

Congo in the early 1960s was the political background to Barbara Kingsolver’s novel The Poisonwood Bible. You sense the presence of McCullin’s images behind her writing just as you can see their influence on the 2015 movie Beasts of No Nation. It is astonishing how many of our most iconic images of conflict and human suffering this one man has caught for the rest of us – the shell-shocked GI in Vietnam, the stampeding British soldiers in a Londonderry street; but then McCullin himself talks of his debt to the 18^th-century Spanish painter Francisco Goya, and Goya’s images of the Spanish Peninsular War. Conflict, and its costs, and the type of people who end up bearing most of those costs, change very little from age to age, and there is at present a particularly awful relevance to these images: in the headlines this morning the perilous consequences for all of us in reinstating a hard border in Ireland; and Trump, sabre-rattling over sending troops into Venezuela

McCullin is now 83 years old, but to say he would reach his eighties would at many moments in his career have sounded ridiculous. One of the very few non-photographic exhibits in the Tate show is the camera that stopped the bullet meant for McCullin at Prey Veng, east of Phnom Penh, in 1968. Like one of those fabled cigarette cases or bibles from the Great War, it’s an artifact that meant one thing and registers now on an altogether different scale. Another series of photographs, from Cambodia, records the last moments of the young man who had been standing in front of McCullin when a shell exploded near enough to pelt them both with shrapnel. Evacuated together by truck from the scene of the shell-strike, McCullin knew when the man had died by the inert rhythm of his feet, bouncing against the floor of the truck. ‘That could have been my corpse rattling there,’ reflects McCullin, who has as resonant a way with words as he has with a camera.

You wonder how McCullin survived not shells and bullets but the emotional cost of a life spent behind enemy lines. There is a case to be made, looking at his photographs, that he didn’t, that for so painfully engaged a photographer, each photograph he took became as much one of his demons as it was his attempt to defend himself against them. This is not an easy show to view by any means; it’s very long, with a room per chapter of the life, pretty much, and it includes photographs no newspaper would publish then or now. But those images are there because the people in them deserve, as the photographer says, a life beyond his archive.

Aside from all its other qualities, the Tate show demonstrates what a master-technician MCullin is. All the prints are silver-gelatin, printed by the photographer himself, and you have never seen blacks so deep, midtones so lambent or brights so dazzling. There is one view in particular, down the valley of a stream near McCullin’s house, the banks starred with snowdrops, the branches nearest to the photographer as black as veins of blood, that is stand-out wonderful. But even now, when landscape has become one of his major subjects, in shots of Hadrian’s Wall or of Glencoe, there is still the memory of conflict, with enormous, gleaming clouds doing battle above the Somerset wetlands and the fields themselves as dark as those of the Somme. McCullin is a hell of a photographer simply of dirt: the banks of that stream, for example; a mud-spattered infantryman; a grimy, starving child; or decades earlier the dirt surrounding a homeless man sleeping on the ground in Spitalfields, surrounded by derelict Georgian buildings that are now, no doubt, million-pound homes. The man’s body seems to be sinking into the dirt, or it is already rising up mercifully to cover him. The late, late still-lifes, of mushrooms or plums from McCullin’s own garden, tiny good things, seem a part of this homage to the earth, to a world that carries on regardless. The show ends with McCullin’s images of what has been left of battered, shattered Palmyra, since ISIS left the city in its wake. These are the photographs an older man might take, of a conflict that has passed on. ‘I can’t explain why I must turn everything into a somber dark image,’ McCullin says, of his own late work, but thank goodness he can’t. If he could, maybe he would have stopped making these images long ago.  JCH

Don McCullin, Tate Britain, until 6 May 2019

Top: Grenade thrower, Hue, Vietnam, 1968

All images courtesy of Don McCullin