In a hotel room in Paris 42 years ago, a little-known photographer from Glasgow captured four young lads from Liverpool having a pillow fight. It was the start of a relationship that would change the photographer’s life forever. Those four lads were The Beatles, and the picture became an iconic image of the Swinging Sixties. The photographer also went on to become a legend, and now Harry Benson’s extraordinary life and work is celebrated in a retrospective exhibition at the Scottish National Portrait Gallery.

In that Paris hotel room, The Beatles song “I Want to Hold Your Hand” had just reached number one in the American charts. After the other photographers had gone to bed, Benson carried on photographing the pillow fight. He processed the film in the toilet of his hotel room, printed it in the bathroom and stayed up till dawn wiring pictures to his newspaper. It was these photographs that would seal the reputation of this young news photographer for the Daily Express. The sense of magic in this, the first of many era-defining images that Benson captured of the Fab Four, endures.

Benson has carved his career out of conflict and celebrity. He shoots stars, big stars – Greta Garbo, Elizabeth Taylor, Winston Churchill – from the time when stardom meant mystery and elegance. From rock idols to riots, Benson has been there – the first emergence of a brash young boxer called Cassius Clay, the funeral of Martin Luther King, Richard Nixon’s farewell to the White House, the collapse of communism in Eastern Europe, the Gulf War, 9/11.

Perhaps his greatest talent is his ability to switch between news photography and portraiture, as in his moving study of the Alzheimer’s-stricken Ronald Reagan with the devoted Nancy alongside. One of his most famous photographs is of the moment Ethel Kennedy looked out in terror and disbelief from beside the prone body of her dying husband, Senator Robert Kennedy.

This retrospective, appropriately named Being There, covers many events that have shaped the past 50 years, and shows that Harry Benson, now 76 and still going strong, really was there.

Frances Anderson