THE mysterious history of one the most famous paintings in Glasgow's collections is being probed by a major new international art project.

For many years there have been question marks over the true creator of The Lady in a Fur Wrap, an enigmatic painting in Glasgow's collections.

It has long been attributed to El Greco, the Greek-born, Spanish-based artist considered one of the finest painters of the Spanish Renaissance.

Now examinations have begun by experts from Scotland and Europe on paintings related to the masterpiece to try and find out more about the painting's history and attribution.

The paintings which could provide clues to the Lady are Portrait of a Knight in Armour, attributed to the Circle of El Greco; Don Juan of Austria, attributed to Jorge de la Rúa; Anne of Austria by Alonso Sánchez Coello, and King Philip II of Spain by Alonso Sánchez Coello and Portrait of a Gentleman, firmly attributed to El Greco.

The Lady in a Fur Wrap was displayed in King Louis-Philippe’s ‘Spanish Gallery’ at the Louvre in 1838–48.

Attributed to El Greco (1541–1614), whose real name was Domenikos Theotokopoulos, it was regarded as an early masterpiece of the painter, believed to be have been painted soon after he settled in Spain in the 1570s.

William Stirling Maxwell, the Scottish politician, 10th Baronet of Pollok, and art historian, praised the portrait in his study Annals of the Artists of Spain (1848), the first scholarly history of Spanish art in English.

He later purchased the portrait at the sale of the French king’s collection in London in 1853.

Since 1967, when Pollok House and most of its collections were given to the City of Glasgow by Stirling Maxwell’s granddaughter, the Lady in a Fur Wrap has been on public display within the House and remains the most famous work in the Stirling Maxwell collection.

However, there is disagreement over who painted the picture, and when, and who is featured in the painting.

In 2004, Gabriele Finaldi, director of the Prado for a time and now director of the National Gallery in England, said it was a "problematic picture", adding: "In other words it looks less and less like an El Greco."

A new statement from Glasgow Life, which runs Glasgow's museums, said the picture is a "conundrum".

It adds: "Direct, informal portraits of Early Modern women such as this are extremely rare and probably unique in a Spanish context.

"Although there is no definitive agreement, this has led some modern scholars to propose a number of new possibilities regarding who painted it."

Now five related paintings are to be studied by a group of experts from the University of Glasgow, Glasgow Museums, the Museo Nacional del Prado in Madrid and the National Trust for Scotland, who care for Pollok House.

The project will explore "questions of artistic technique, attribution and identity, using scientific analysis as well as research methods involving the history of dress, society and collecting".

Duncan Dornan, head of Glasgow Museums, said: "We are pleased to partner with the foremost experts in the field of Spanish art to gain a fuller understanding of this iconic painting’s creation through comparative study of related works in our collection.

"We look forward to learning more about these major paintings of the Spanish Golden Age, including one of Glasgow Museums’ most popular and internationally recognised artworks.”

Dr Mark Richter, University of Glasgow, who is coordinating the scientific investigation, said: “Although there is no guarantee of definitive results through technical analysis we will at the very least learn much more about how this most enigmatic portrait was painted and the relationship of its materials and methods of creation to those of other important pictures in this and other collections, as well as to the main writings on art theory and practice at this period.”

The scientific examination presently being undertaken at Glasgow Museums Resource Centre includes examination of the five paintings’ surface, as well as analysis of microscopic paint samples.

Experts from Glasgow University, Historic Environment Scotland and the Doerner Institut, Munich, will carry out advanced analytical techniques, including Gas Chromatography Mass Spectrometry, a procedure which is ideal for providing detailed chemical information on the organic materials found in paint samples, especially binding media.

Other techniques, such as infrared reflectography, promise to increase our understanding of any preliminary sketches or underdrawings by the artists, which are often hidden by opaque overlying paint layers.

Earlier this month X-radiography on some of these works was carried out at the University of Glasgow’s School of Veterinary Medicine.

The Lady in the Fur Wrap has already been examined at the Prado, when it was included in the museum’s exhibition, El Greco and Modern Painting, 2014.

Dr Hilary Macartney, who is leading the research at the University of Glasgow, said: “Other lines of enquiry, such as research on dress and jewellery, the status of people represented in portraiture in this period, and history of collecting will be equally important, and the project therefore brings together leading scholars of Spanish art, dress and related historical fields to debate and assess the latest research.

"The fascinating history of the fame of the Lady in a Fur Wrap and its impact on modern art and even film is likewise being studied.”

A three-day symposium announcing the findings of the research is anticipated in early 2019, with the publication of an edited book expected to follow in 2020.