This picture relates to the portrait of Anne Sophia, Countess of Carnarvon with her brother (?), Philip, Lord Herbert, later 5thEarl of Pembroke (Derbyshire, The Duke of Devonshire and the Chatsworth Settlement Trustees, Chatsworth).  Oliver Millar believed that the portrait of Anne could have derived from a lost half-length portrait, now known only through an engraving by Pierre Lombart, executed for his series of Countesses after Van Dyck's portraits (O. Millar, in S.J. Barnes et. al., Van Dyck, A complete catalogue of the paintings, New Haven & London, 2004, p. 457, under no IV.41).

Anne was the eldest daughter of one of Van Dyck's greatest English patrons, Philip, 4th Earl of Pembroke. Her father, a court favourite of both James I and Charles I, rebuilt Wilton House, Wiltshire, with the help of Inigo Jones and formed one of the finest picture collections in England. The Countess of Carnarvon married Robert Dormer, later 1st Earl of Carnarvon (circa 1616-43), in 1625. Shortly after the marriage, Dormer set out on a grand tour visiting Europe and the Middle East. Upon his return the couple settled into life at Court and the Countess performed regularly in the Queen's masques. They owned a great house, Ascott, near Wing, as well as one in London where their son, Charles, was born in 1632. The Earl of Carnarvon, who was Chief Avenor, or Keeper of the King's Hawks, served on the Royalist side with distinction during the Civil War, taking part in the battle of Edgehill in October 1642 and the assault on Chichester the following year. He was killed at the first battle of Newbury on 20 September 1643. His body was carried to Oxford and he was buried in Jesus College chapel. The Countess died in 1695.

Among the other portraits by Van Dyck commissioned by the Earl of Pembroke is the celebrated group portrait of his family, the largest surviving work by the artist, which remains at Wilton. The Countess was first painted by Van Dyck in a full-length portrait which is thought to have been painted for Sir Edmund Verney (ibid., no. IV.40).