A painting of John Ruskin which led to the end of the art critic's marriage has been acquired by the Ashmolean Museum.
The portrait by John Everett Millais has been described as one of the most important pre-Raphaelite paintings that remained in private hands.
The Victorian era love triangle began when Millais fell in love with the sitter's wife Effie, while he painted Ruskin and holidayed with the couple in the Trossachs in Scotland in 1853.
The Ruskins' marriage was annulled the next year on the grounds that it had not been consummated and Millais went on to marry Effie.
The couple had eight children together but Effie's reputation never recovered and she was shunned by polite society.
Finishing the painting was to become for Millais "the most hateful task I have ever had to perform".
The love triangle is the subject of a film, Effie Gray, written by Emma Thompson and starring Dakota Fanning, Tom Sturridge and Julie Walters, set for release later this year.
Ruskin gave the portrait, which was not exhibited at the Royal Academy in 1854 despite expectations, to a friend and it was bought by the late owner for a record price at auction house Christie's in 1965.
The painting has been on loan to the Ashmolean, in Oxford, since 2012 and has been allocated to the museum by Arts Council England under the Acceptance in Lieu of Inheritance scheme.
Ashmolean Museum director Christopher Brown said: "We are hugely grateful to the Arts Council for their support in allocating this extraordinary picture to the Ashmolean.
"The portrait is of supreme importance for the study of 19th-century British art and it will be shown with the Museum's world-renowned Pre-Raphaelite collection."
Arts Council England chair Peter Bazalgette said: "It's wonderful that such a celebrated portrait is now on permanent public display at the Ashmolean Museum.
"This was one of the finest pieces at the Tate's sell-out exhibition on the Pre-Raphaelites, and can now be admired by even more people."
Culture Minister Ed Vaizey said: "The Acceptance in Lieu scheme has seen literally thousands of treasures enter our national collections since its inception.
"Millais' John Ruskin portrait has the most fascinating history, and I'm delighted this stunning work has found a new home in the Ashmolean Museum. "
The Acceptance In Lieu Scheme allows people to pay their inheritance tax bill by transferring important cultural, scientific or historic objects to the nation.