A self-portrait by the artist Rembrandt has gone on display at the Ulster Museum in Belfast.
It is not known how much Self Portrait At The Age Of 63 is worth, but similar works typically fetch more than £20 million at auction, with some even hitting up to £100m.
The piece, which was painted in the final year of the Dutch master's life, was unveiled yesterday as part of the National Gallery's Masterpiece Tour. It will remain on display until March 13, with entrance to the exhibition free.
National Museums NI curator of fine art Anne Stewart said: "We are delighted to have been selected as the first venue on the National Gallery Masterpiece Tour to showcase Rembrandt's Self Portrait At The Age Of 63.
"One of his most famous self-portraits, this incredible work of art is considered one of his most important and poignant.
"There is an intensity and pride about the painting, as well as deep pain and sadness.
"There is a strong sense that this was a self-portrait by someone who knew he was close to the end of his life.
"We were so excited when we found out the painting was coming to the museum. I think we can be quite certain in saying that it is the most important painting we have had on display, which is quite a large claim to make.
"We have had drawings by Leonardo da Vinci, but in terms of paintings we have never really displayed this quality, certainly not in my memory of being here."
Mary Hersov, national programmes manager for the National Gallery in London, added: "I'm not really in a position to talk about the value of the painting - none of our pictures are for sale. In fact, legally we are not allowed to sell them, and it isn't something we would consider, really. Certainly, it is one of the greatest self-portraits by one of the greatest artists of all time."
Ms Hersov also said she was not in a position to comment on the complex process required to move such a precious piece of art.
But she added: "It is a highly complicated and well thought-out practice, and we're very careful with how we manage this." In 2009 the Rembrandt painting Portrait Of A Man, Half-Length, With His Arms Akimbo, fetched £20.2m, being bought by an anonymous client bidding via telephone. It was the first time the artwork had gone under the hammer since 1930, when it sold for £18,500 - a large sum then. Before the pre-sale exhibition it had not been displayed in public for 40 years.
The previous world record price for a Rembrandt work was £19.8m.
Portrait Of A Lady Aged 62 was sold at Christie's in London in December 2000.
However, the online art magazine, theartwolf.com, values some of Rembrandt's other works, all of which are privately owned, at a much higher price.
Portrait Of Jan Six, dating to 1654, is described by the website as "one of the best portraits from the Dutch Golden Era".
It said the piece of art had been valued by art dealer Otto Naumann "in excess of $150m" (£105m).
The website also values an earlier self-portrait of Rembrandt from 1659 at between $100m (£70m) and $150m.