Newcastle taxi driver Kempton Bunton picked up the painting in August 1961, just 19 days after it was exhibited.
He sent ransom demands saying he would return the painting if more money was spent looking after the elderly, with a particular focus on free TV licenses.
The Duke of Wellington was surrendered nearly four years after his robbery, with Bunton’s lawyer successfully arguing that his client never intended to keep the painting and that the man was only convicted for have taken the frame.
To mark the anniversary of the theft, the National Gallery released photographed materials, including a reward notice from the Metropolitan Police, a handwritten ransom note, and a statement on the gallery’s position following the ransom demands.
They take place at the gallery’s research center. The painting itself is currently on display in Room 45.
The portrait, which was painted after Wellington’s victory at the Battle of Salamanca in 1812, was acquired by the state after the government intervened to prevent it from being bought by an American tycoon.
The theft was referenced in the 1962 James Bond film, Dr No, in a scene in which the painting was on display in the titular villain’s lair, suggesting he had stolen the work.
Bunton’s take of the portrait will be explored in The Duke, a movie to be released next year, starring Jim Broadbent and Dame Helen Mirren.
Director Roger Michell said: “It’s amazing to think that this painting was once hidden in the back of a cabinet in Newcastle. And perhaps even more amazing that 60 years later I was able to make a film about how it ended up there!
“It’s a story that makes a lot of laughs (and a few tears), undoubtedly boosted by the brilliance of Jim Broadbent and Helen Mirren. There’s also a delicious twist that I can’t wait to share with audiences when the film finally hits theaters next spring.
“In the meantime, enjoy Goya’s painting as it was meant to be enjoyed: hanging on the wall of the National Gallery.”
Bunton died in Newcastle in 1976.