A portrait of Sinn Fein leader Gerry Adams has been purchased by London's National Portrait Gallery.

The portrait was created by Cumbrian artist Conrad Atkinson during trips to Northern Ireland in 2007 and 2008.

Atkinson told TheJournal.ie that those trips, in which he met several figures involved in the peace process, were more positive than his first experience in the region during the 1970s at the height of the Troubles.

When his painting, 'Silver Liberties,' which focused on Bloody Sunday, arrived at the Ulster Museum in 1978, the staff refused to touch it or display it.

The artist recalled that when he was commissioned for the work he said, "Fine - but there'll be trouble."

He was right.

"I had to be escorted on the streets," he says.

His portrait of Adams was created with acrylics, watercolors and oil pastel and includes words in the Irish language by Bobby Sands about birds singing. A bird is in the top left corner.

Says Atkinson, "In my recent visits to Northern Ireland, the most radical thing I have noticed is the spread of the Irish language – you now see signs in English and Irish."

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While Atkinson describes the National Portrait Gallery as "courageous" for purchasing the painting and says he is "honored" to have his work displayed there, he notes that the decision has attracted negativity.

Critics have written to the gallery comparing a portrait of Adams to Hitler and Osama bin Laden.

Atkinson disagrees.

“Gerry Adams, Martin McGuinness and Ian Paisley are all part of the peace process,” he said.

He adds that the region has more to offer than its tragic and violent past.

“That’s what this portrait represents – in its use of Irish language and the imagery. This place, Northern Ireland, which isn’t any bigger than Lewisham but has this continental culture that’s rich and beautiful.”