Oil on canvas, 119.4cm by 94cm.
William Cecil, 16th Baron Roos (1590-1618), was the only son of William Cecil, 2nd Earl of Exeter (1566-1640). He inherited the Roos barony from his mother Elizabeth (née Manners) when he was only a year old, but never inherited the Earldom of Exeter. He died without issue, survived by both his father and his grandfather, Thomas, 1st Earl of Exeter (1542-1623), and the title eventually passed to one of his cousins.
The portrait appears in the 1763 Burghley Inventory: “The Marble Hall….Ld. Roos, by Sr. Peter Lilly”.