Against a walL in the City of London a man stands ramrod straight in a city suit, bowler hat in one hand and box of Swan Vestas in the other, with a sign reading: “NO DOLE. WORK WANTED. Lost all in Business.” Business has ruined him, now he’s begging from business – an irony that will have appealed to the photographer, Dora Maar.

Dora Maar? The Weeping Woman, mistress of Picasso? One and the same. Before taking up with the Spanish painter in 1936, Maar was a chic young photographer shooting fashion spreads, ads for Ambre Solaire and nudes for French revues de charme. The match-seller was one of a series of social documentary photos shot on the streets of Barcelona, Paris and London in the early 1930s.

Of all Picasso’s so-called muses, Maar was the most multifaceted. Born Henriette Markovitch in Paris in 1907 to a Croatian, possibly Jewish, architect father and a French Catholic mother, she grew up in Argentina before returning to Paris aged 19 to study decorative arts and painting before switching to photography, perhaps because it was easier to earn a living. Whatever the reason, the medium suited her quick eye. As a documentary photographer, she might not have stood out in a stellar generation that included Brassaï, Henri Cartier-Bresson and Robert Capa; it was the magic she performed in the darkroom that set her apart.