Edvard Munch’s most angst-filled moment may well not be represented by his best known work, The Scream. Another painting in a British Museum exhibition that opens on Thursday holds the key to a moment of greater drama and violence in the Norwegian painter’s troubled life.

In 1902 inside the bedroom at the home of his fiancee, Tulla Larsen, an argument escalated and shots were fired. Munch, who sustained a bullet wound to his left hand in the scuffle, later sawed his portrait of the two of them in half. Now visitors to the museum will be able to see the two pieces side by side.

“He did this extraordinary portrait at the height of their relationship,” said the curator Giulia Bartram. “He looks red-faced and she looks pretty fed up. The halves have remained in the Munch family.”

Bartram hopes visitors will see the significance of the work and she argues that Munch’s portraits of women are the unsung stars of the new show. “Munch had hugely complicated relationships with women,” said Bartram. “He almost physically feared them. He was nervous about commitment to the point of neurosis. And perhaps his most torturous relationship was with Larsen.”

Larsen, the daughter of an affluent wine merchant, pursued him around Europe.

“Their relationship went on for about four years and she was the only woman to whom Munch was actually engaged,” said Bartram. “Although he spent most of his time trying to run away from her. His relationships with women can be found throughout his work, although these paintings have been overshadowed by the fame of The Scream. If it wasn’t for these women, he might not have been such a brilliant artist or created such visceral work.”

The injury to the painter’s left hand was the subject of one of the very first medical X-ray photographs taken and it captured the image of the bullet. Munch later said the shooting had only happened because he was drinking too much; but, warns Bartram, he often wrote and rewrote the facts of the more significant incidents in his life.