Art experts have confirmed that a portrait in the collection of the National Gallery of Canada, its authenticity long questioned, was painted by the Venetian master Titian.

The painting Daniele Barbaro (1545) will be displayed at the NGC in Ottawa beginning Friday, after an extensive restoration.

Experts say the portrait of Daniele Barbaro (1545), now on display at the National Gallery of Canada, was painted by the Venetian painter Titian. (National Gallery of Canada)

The portrait is of Daniele Barbaro (1514-1570), an Italian scholar and humanist, and was painted for the historian Paolo Giovio, Bishop of Como in Italy, who owned a collection of portraits.

Barbaro himself commissioned Tiziano Vecellio, called Titian and recognized in his time as one the greatest artists of the age, to do the painting.

When the NGC bought the painting in 1928, it was believed to be a Titian. Letters between the bishop and Barbaro confirmed its history.

But there is another painting of Daniele Barbaro in Spain’s Prado Museum and scholars were divided on whether both works were by Titian or if the NGC portrait was a copy by one of his acolytes. In 1991, the two paintings were compared side-by-side at a specially arranged meeting and experts decided the NGC was not by the Venetian master.

But a recent restoration revealed the sensitivity and skill used in painting the NGC portrait.

Stephen Gritt, NGC director of conservation and technical research, arranged to work with an expert at the Prado to compare the two paintings again. X-ray images showed the underlying images, including ways that the painter had adjusted the collar height and repainted the sitter’s prominent nose.

"I spent an afternoon in front of a light-box with the Prado's technical documentalist,” Gritt said in a statement.

“By painstakingly comparing subtle features of execution as revealed on the X-ray, we were able to demonstrate that while the paintings were painted more or less at the same time, the Ottawa canvas was the one with all the thinking in it, the one that leads the way," he said.

The conclusion was that the paintings were painted side by side, but that the NGC’s portrait was the one where Titian had worked out details such as colour and composition, and it was most likely finished with Barbaro present.

The painting will be displayed through the holiday period.