THE mystery of who painted a famous Glasgow artwork has finally been revealed after four years of research.

For more than 100 years debate has raged over who painted Lady in a Fur Wrap, owned by Glasgow Museums.

It was traditionally believed to have been by El Greco but technical examination carried out by Museo Nacional del Prado, Madrid, and Glasgow University now means Alonso Sánchez Coello is being given the credit.

Duncan Dornan, Head of Glasgow Museums part of Glasgow Life, said: "The Lady in a Fur Wrap is a fascinating portrait.

"This technical study has also, excitingly, revealed unexpected elements such as traces of underdrawing hidden behind the surface.

"These suggest a different style of dress for the Lady, before the eye-catching fur cape was introduced.

"These are all elements that continue to attract debate and although we now understand who painted the work the identity of the mysterious lady is still unanswered."

Lady in a Fur Wrap was purchased by Sir William Stirling Maxwell in 1853.

It is one of an important collection of Spanish works, which together with Pollok House, was donated to the City of Glasgow in 1967 by Sir William’s granddaughter Dame Anne Maxwell Macdonald.

It is planned the painting will return to Pollok House, run by the National Trust for Scotland, in summer 2020 with a fresh interpretation.

The Lady in a Fur Wrap has fascinated viewers ever since it was exhibited in the Louvre, Paris, in 1838.

Since the beginning of the 20th century, however, it has presented a conundrum.

Increasingly, scholars in the field of Spanish Art thought the Lady looked different from other paintings known to be by El Greco.

This led them to propose a number of new possibilities regarding who painted it, when and who is featured in the painting.

Using the opportunity of the Lady in a Fur Wrap being on loan to the Prado in Madrid for the 2014 celebrations for the 4th centenary of El Greco’s death, technical examination of the painting was carried out at the museum that year.

A comprehensive research project was set up in Glasgow to unpack the complex history and significance of this unique painting.

Dr Hilary Macartney, who led the research at the University of Glasgow, said: "Other aspects in addition to the paint analysis have been crucial in concluding our findings.

"The case for attributing The Lady in the Fur Wrap to Sánchez Coello takes into account a range of factors, including stylistic characteristics.

"Sánchez Coello is most closely associated with conventional, formal royal portraits, however we now believe that he was also responsible for portraits of a different and more informal character, such as the Prado’s Unknown Young Woman, as well as The Lady in the Fur Wrap, which combined intimacy and current ideals of female beauty.

"Together with leading scholars of Spanish art, dress and related historical fields we deliberated over features including dress and jewellery and the status of people represented in portraiture in this period.

"It is only in considering all these aspects that we have been able to attribute this outstanding portrait to Alonso Sánchez Coello."

Head of Spanish Renaissance Painting, Museo Nacional del Prado, Dr Leticia Ruiz Gómez, said: "A conclusion has been reached that the Lady in a Fur Wrap is neither the work of El Greco, nor Sofonisba Anguissola, but the work of Alonso Sánchez Coello.

"I think this is a splendid Sánchez Coello."