Anthony van Dyck, 'The Giustiniani Children (?)', 1626-7

Three dashing young boys stand on the steps of an impressive building, with classical columns behind them and velvet drapery looped up like a curtain drawn up to reveal them in all their finery. During the six years Anthony van Dyck spent in Italy (1621–27) he frequently stayed in Genoa, where he received many portrait commissions from the city’s elite. He painted his sitters in luxurious settings, often flattering them, and introduced a new style of portraiture.

The boys were long believed to represent the Balbi children because the painting was once in the collection of the wealthy ​Balbi family ​in Genoa. But new research suggests these boys belonged to another prominent Genoese family: they are in fact Alessandro (1617–1674), Vincenzo (1619 – after 1690) and Francesco Maria (1624 – after 1651) Giustiniani Longo.

The three brothers wear extremely expensive garments of predominantly Spanish fashion – made of satin, velvet and brocade, decorated with silver and gold braid, with fine linen ruffs, collars and lace cuffs – and they seem full of life, ready to be off at any moment. The youngest boy, Francesco Maria is still dressed in a full-length infant’s dress. Little boys wore them until they were put into breeches at about the age of five. His chubby cheeks and hands also mark him out as an infant, and he clumsily grasps a defenceless bird in his fist.

The middle brother, Vincenzo, places a protective hand around the younger boy’s shoulder. His right hand is on his hip, his hair is fashionably long and casual and he has a faraway look in his eye. His costume was also in vogue: gold frogging across the chest, narrow long breeches and a plain flat linen collar. His pose and dress seem to mark the boy as the stylish second son, with fewer responsibilities than his older brother.

Alessandro, the eldest boy, stands a little apart from the others. He carries his dress sword with assurance and is the most ornately but also most traditionally dressed of the three. His costume, consisting of a red doublet decorated with silver thread with a matching cloak, a silver and red cassock, worn on top of the doublet, and matching full-cut puffed and slashed breeches with bright red hose (stockings), is a symbol of his status.

He gestures towards two pet birds on the lowest step – they both originally had a bell attached to one of their legs. They are choughs and were perhaps intended to play a similar role to other tamed birds found in portraits of children, their willingness to learn symbolising a good upbringing and education. Choughs were also renowned for remaining loyal to their mates even after death. As such they may have been intended as a symbol of fidelity. The bird clutched by the youngest child in the centre of the composition perhaps recalls the inscription on an ancient gravestone: ‘Life is like a little bird which is held in the hand of a boy; it often flies off at the very outset'. This could refer to the infant death of the brothers’ sibling, Luciano.

Van Dyck’s fine highlights and sensitive modelling show us what each bright-eyed boy looked like, but it is his subtle and delicate observation of their movements and interactions that conveys their personalities in a groundbreaking way. He formulated a new style of portraiture that was hugely influential for centuries to come.