A previously unseen self-portrait by Lucian Freud has gone on display at the National Portrait Gallery.

The unfinished painting, which is thought to date back to the mid-1980s, is being exhibited alongside a selection of drawings from Freud‘s unseen sketchbooks.

They have gone on display after the late artist’s estate left them to the nation in lieu of inheritance tax.

Lucian Freud Unseen, which runs until September 6, shows highlights from an archive of letters and 800 drawings which date from the 1940s to the 1990s.

Some studies on display are connected to major works byFreud, including one sketchbook containing a drawing of Lady Caroline Blackwood which relates to the painter’s 1954 masterpiece Hotel Bedroom.

Also on show are drawings charting Freud‘s boyhood in Berlin and an illustration for the cover of his daughter EstherFreud‘s 1992 novel Hideous Kinky.

Undated handout photo issued by the National Portrait Gallery of a previously unseen self-portrait by Lucian Freud, which is to go on display at the gallery as one of a selection of drawings from Freud's unseen sketchbooks. (Photo credit: NPG/PA Wire)

Undated handout photo issued by the National Portrait Gallery of a previously unseen self-portrait by Lucian Freud, which is to go on display at the gallery as one of a selection of drawings from Freud’s unseen sketchbooks. (Photo credit: NPG/PA Wire)

Sarah Howgate, senior curator of contemporary collections, said: “This exciting and extensive body of valuable material will greatly expand our holdings of works by Freud in our collection and help us to further understand the studio practice of an artist whose focus and preoccupation was the portrait.”

National Portrait Gallery director Dr Nicholas Cullinan added: “I am delighted that a selection from this important and extensive archive, of the sketchbooks and letters of Lucian Freud, together with the self-portrait fragment, is now on display at the National Portrait Gallery.”

Freud, who died in 2011 aged 88, was the grandson of psychoanalyst Sigmund Freud and the brother of the late television personality Sir Clement Freud.

He was born in Berlin in 1922, but his Jewish family fled the city in 1933 and he became a British citizen in 1939.

The realist painter was educated at the Central School of Art, London, the East Anglian School of Painting and Drawing in Dedham and Goldsmiths College in London.

Undated handout photo issued by the National Portrait Gallery of a drawing by Lucian Freud titled Sleeping Girl, which is to go on display at the gallery as one of a selection of drawings from Freud's unseen sketchbooks. (Photo credit: NPG/PA Wire)

Undated handout photo issued by the National Portrait Gallery of a drawing by Lucian Freud titled Sleeping Girl, which is to go on display at the gallery as one of a selection of drawings from Freud’s unseen sketchbooks. (Photo credit: NPG/PA Wire)