It will now go on display at The Charles Dickens Museum in London from the autumn.
The watercolour on ivory of the author by artist Margaret Gillies (1803-87) had last been on public view in 1844 when exhibited in London. It only came to public knowledge again last year when its owner contacted London dealership Philip Mould to help confirm its true identity.
The dealership researched the miniature with the museum and discovered it had been painted by Gillies over six sittings in 1843.
After the publication of A Christmas Carol, Gillies’ portrait was exhibited at the 1844 Royal Academy Summer Exhibition and became a defining image of Dickens at the time.
But the 176-year-old watercolour was later taken overseas and its attribution lost.
It was then found in a tray of trinkets at a general auction in South Africa in 2017.
Covered in mould, the owner bought it with the tray of miscellaneous objects for just £27. He then contacted Philip Mould to help uncover its provenance and sold it to the dealership which then helped launch the fundraising campaign for the museum to buy the picture.
It will now go on display from October 24 after the target of £180,000 was reached.
The museum received donations and grants to help with the purchase including from Art Fund and the Arts Council England/V&A Purchase Grant Fund.
Dr Cindy Sughrue, director of the Charles Dickens Museum, said: “We are so excited to be bringing the ‘lost’ portrait home and are extremely grateful for, and touched by, the generous support that we have received from individual donors all over the world. It is a magnificent affirmation of the enduring appeal of Dickens’ writing and the worldwide fascination that he continues to inspire.”
Sughrue added: “This is a vibrant portrayal of Dickens, at 31 years of age, already known the world over but with so much still ahead of him and in the midst of writing arguably his best-loved work, A Christmas Carol.”
Philip Mould said: “Dickens’ astonishing re-emergence, not least from beneath an obscuring wall of fungus, could never have been predicted. We are thrilled he is finally checking into his London home after such a global adventure - it is an epic tale with a supremely happy ending.”
Art Fund director Stephen Deuchar said: “Thought lost for over 170 years, this important portrait can now be enjoyed by visitors to the museum for years to come… It will brilliantly animate the story of his life and works at his former home in Bloomsbury.”