Oil on canvas, 127cm by 152.4cm.
In 1643, during the Civil War, Parliamentarian forces attacked Burghley, where Viscount Campden and a troop of Royalist cavalry were known to have sought refuge.
At the time, the 4th Earl of Exeter was a boy of fifteen.
He later married Lady Frances Manners (1636-1660), daughter of John, 8th Earl of Rutland.
They would become the parents of John, the 5th Earl (1648-1700), one of the two great collectors at Burghley.
The Dutch-born artist arrived in England as a young man and remained here for the rest of his life.
He succeeded Sir Anthony van Dyck (1599-1641) as the most fashionable portrait painter of the day, working as court painter to Charles I.
He then spanned the period of the Commonwealth or Interregnum, when he painted both Oliver and Richard Cromwell, before being appointed Principal Painter in Ordinary to Charles II at the Restoration.