This is almost certainly the ‘Lady in a white garment, a little hat on her head and a jewel with a crown on it on her side, full-length, 6ft 9in x 3ft 9in’ recorded in the 2nd Privy Lodging at Whitehall Palace in 1666 (no 229). The size given here matches the central original part of the canvas, which has obviously been extended on either side. The portrait can be traced at various locations through the 18th century, ending up in the Queen’s Drawing Room at Hampton Court in 1861, when it is identified as ‘the daughter of Frederick of Denmark’.

Princess Hedwig was the youngest daughter of Frederick II and the sister to Anne of Denmark, James I’s Queen. She married the Elector of Saxony in 1602 and after his death in 1611 wielded considerable power and exploiting her relations with the English and Danish crown to keep her territories out of the Thirty Years’ War. The sitter is shown full-length, possibly in white mourning, which would date the portrait to the years 1611-20. She wears a white gown and a tall plumed hat, with a double rope of pearls across her stomacher and a jewelled crowned S suspended from a gold chain at her breast.