A portrait redolent of one of the most famous romances of the Victorian era has surfaced for sale from a private collection in Scotland where it has been, unrecorded and unknown to scholars, for over a hundred years.

Painted in 1869 by the pre-Raphaelite artist Dante Gabriel Rossetti, it represents his muse, Jane Morris, who was married to Rossetti’s business partner, the artist and designer William Morris.

Artist and sitter first met and were attracted to each other in 1857, but as Rossetti was already engaged to Elizabeth Siddall, she married Morris instead. However, after Siddall tragically took her life in 1862, and the Morris marriage appeared to flounder, the relationship was rekindled.

The year 1869 is generally thought to be when Rossetti reconciled his grief for Siddall with his love for Jane Morris. Though gossip levels ran high, lack of documentary evidence has left historians guessing at the degree of intimacy achieved between them.

Each destroyed the correspondence with the other during those crucial years. The title of the painting, ‘The Salutation of Beatrice’, associates Jane with Dante’s Beatrice, the incarnation of beatific love and the object of Dante’s courtly love. A sonnet by Dante pinned to the wall extols the virtues of courtly love: ‘My lady looks so gentle and so pure…’

The highest price for Rossetti is the £2.6 million paid by Australian collector, John Schaeffer, in 2000 for a pastel drawing of Jane Morris entitled ‘Pandora’, also dated 1869. He subsequently re-sold it in 2004 for £1.7 million. The rediscovery, which is a rare oil painting, is estimated to fetch between £1 million and £1.5 million at Christie’s next month.