“Life isn’t made of stories that you cut into slices like an apple pie,” Magnum Photos co-founder Henri Cartier-Bresson told Popular Photography magazine in 1957. “We have to evoke a situation, a truth. This is the poetry of life’s reality.” Established in 1947 in the aftermath of World War II, Magnum’s mission was to lend reportage the human element of artistic photography. Never before had photographers sidestepped the controlling influence of the commissioning editor and worked independently, retaining the rights to their own images. Ever since, the agency has remained true to its core ethos and along the way recruited some of the foremost photographers of the 20th century, such as Elliott Erwitt, René Burri and Werner Bischof. But it is the work from Magnum’s first decade—a portfolio of which we present here—that perhaps carries the greatest iconoclastic thrill. According to Sophie Wright, the head of Magnum’s cultural department, this is because many of the photographs now have the power of historical documents. “I love the print as object as well as image,” she says, referring to the marginalia, stamps and scribbles that adorn the reverse sides of many archive prints. “You have photographers writing the captions, you have editorial instructions… they have that heritage, that provenance.” Though Magnum’s New York archive was sold to Michael Dell (the founder of Dell Computers) in February of this year, many classic prints from the agency’s nascent period are still available to buy. Early Magnum, opening April 7 at London’s Magnum Print Room, features a wide selection, including works by Cartier-Bresson and fellow founders Robert Capa, George Rodger and David “Chim” Seymour.