(Updated, January 2019) A three-quarter-length portrait standing to left facing forwards. His left hand is on his hip, his head turned towards the viewer wearing a long dark brown wig. He wears a white lace-edged collar and the robes of a Knight of the Garter (dark blue lined with white), which he became in 1642. The order's chain and 'great George' (the large-pattern badge of St George slaying the dragon) are round his shoulders. His sword is visible hanging from his left side. A fluted column is behind.

A younger son of Elizabeth, the 'Winter Queen' of Bohemia, and a nephew of King Charles I, Rupert fought on land for his uncle throughout the Civil War (1642-49) principally as a cavalry commander, and became commander-in-chief of the Royalist land forces in 1644. At the end of the war he took command of the loyalist remnants of the fleet and, despite defeat by Blake in 1650, carried on the conflict for several years based in the Channel Islands. Under Charles II, he held commands in the regular navy, fighting in the Second and Third Dutch Wars and becoming Lord High Admiral on the Duke of York's enforced retirement in 1673. He was a man of some artistic talent and intellectual curiosity, and (like his cousin Charles II) a patron of science, often conducting experiments himself. He was a Fellow of the Royal Society, founded by Charles II, and spent his last years as Governor of Windsor Castle which gave him some scope for testing his ideas about artillery..

Lely, a Dutchman who arrived in England in 1641 after the death of Van Dyck, soon became his successor as leading portraitist of the day. He worked for Charles I, continued to flourish under the Commonwealth and Protectorate, and after the Restoration of 1660 was appointed Principal Painter to Charles II. Rupert is thought to have sat only once to Lely for a head study that became the basis of subsequent portraits, painted substantially by Lely's studio assistants. This one, inscribed 'Prince Rupert', is the version that towards the end of his life Rupert gave to Thomas Bennett, his secretary. It was purchased in 1971, at auction by Sotheby's, to which it had been consigned by the diplomat Sir Anthony Rumbold (10th baronet, 1911-83).