Probably by Pieter van Coninxloo, 'Philip the Handsome', about 1493-5

These fair-haired teenagers were brother and sister, the heirs of royalty and future rulers themselves. Philip the Handsome and Margaret of Austria were the children of the Holy Roman Emperor, Maximilian I, and Mary of Burgundy. They are identified by inscriptions in gold around their heads and by the coats of arms on the shields at the tops of the panels. Around them are a further 17 smaller shields representing the states and towns their parents governed.

Philip (1478–1506) wears the livery collar of the Order of the Golden Fleece (a prestigious chivalric order, founded in the 1430s by Philip the Good, Duke of Burgundy) which he received in 1481; it also surrounds the top shield, which shows his father’s coat of arms on the left and his mother’s on the right. The coats of arms around him are those of Maximilian’s possessions in Austria, Slovenia, Switzerland, Italy, Germany and Alsace. Not all are accurate: the labels for Upper Austria and Schelklingen have been mixed up and the arms of Alsace are back to front.

Margaret (1480–1530), who was to become one of the effective rulers of her day as regent of the Netherlands, was clearly unmarried when this painting was done: half of the lozenge-shaped shield at the top of her panel is left blank, waiting for her husband’s arms. The shields around her display the arms of her mother’s Burgundian territories.

Collecting portraits of relatives and prospective spouses was an important feature of late medieval court culture: in an pre-photographic era this was often the only way people got to see who they were to marry before they met them. This small diptych was easily portable, and was probably done in the early 1490s, when portraits of Philip and Margaret would have been much in demand as various projects for their marriages were matters of intense concern. A very similar diptych, now at Schloss Ambras in Austria, gives their ages as 16 and 14, so can be dated to between 22 July 1494 and 10 January 1495. The National Gallery’s diptych was clearly painted at about the same time.

These paintings were once very colourful but are now obscured by layers of discoloured varnish. The brownish backgrounds seem originally to have been red, and Philip’s hat was also red; it has been overpainted in black. The blue areas in the coats of arms have darkened and the gilded details have lost their shine. They also had broad green frames, now missing.