Van Dyke revelled in depicting the elaborate costumes of the era
A portrait by Anthony van Dyck, thought lost by experts, is on public display for the first time in over a century.
Tate Britain has launched its new exhibition of Van Dyck works which includes the 17th Century painting of Katherine, Lady Stanhope.
After a 1929 private sale it was officially logged as "whereabouts unknown" but turned up again at auction in New York in 2006.
The exhibition opens to the public in London on 18 February.
Sir Anthony van Dyke was born in Antwerp but became the leading painter in the court of art-loving King Charles I. His depictions of the king shaped history's view of the Stuart monarchy.
His painting of Katherine, Lady Stanhope, later Countess of Chesterfield, was carried out in 1635 or 1636.
There is some evidence that artist and sitter were romantically involved as a contemporary letter by someone who knew the pair speaks of van Dyck's "gallantrye for ye love of that Lady."
The Royal Collection, The National Trust and many private lenders have loaned works to the exhibition which focuses on the work van Dyck did after settling in England.
The exhibition reunites 17th Century aristocratic family members. It is thought that the portraits of Katherine, Duchess of Buckingham and that of her two sons, George 2nd Duke of Buckingham and Lord Francis Villiers have not been displayed together before.
There are 60 works by van Dyck on view including the rarely-seen Self-portrait circa 1640.
The artist revolutionised portraiture in Britain. The exhibition also includes portraits by later artists including Sir Joshua Reynolds and John Singer Sargent, to demonstrate van Dyck's huge influence over the centuries.
In all, over 130 works are on display. The exhibition continues at Tate Britain until 17 May.