'Lesson Number One: it’s the pictures that baffle and tantalise you that stay in the mind forever .'

Andrew Graham-DixonCupid and Psyche, 1639–40, by Sir Anthony van Dyck (1599–1641), 74in by 77in, Her Majesty Queen Elizabeth II

Andrew Graham-Dixon says:

I remember my mother taking me to see this painting when I was a little boy. We used to feed the ducks in the Round Pond in Kensington Gardens and then go into Kensington Palace, where it used to hang (and still does, mostly). I suspect the tragic subject and sexual undertones – maybe that should be overtones – were lost on me. I was stunned by the colour and energy and excitement of the painting and by the sense that Something Important was going on, although what it might be I could not guess. Lesson Number One: it’s the pictures that baffle and tantalise you that stay in the mind forever .

Andrew Graham-Dixon is an art historian and broadcaster. His new BBC4 series Art, Passion & Power: The Story of the Royal Collection runs every Tuesday until February 6

John McEwen comments on Cupid and Psyche:

Venus, goddess of love, was jealous of the beautiful, but mortal Psyche. She ordered Cupid, god of love, to make the girl fall for the most despicable of all men, but Cupid was secretly stricken by Psyche. He took her to an enchanted spot and visited her incognito every night. She promised him never to ask who he was, but, when she confided in her jealous sisters, they said he must be a monster to need to hide himself. Thus, when he slept, Psyche looked at him by the light of a lamp and saw he was gorgeous. He awoke and her betrayal was revealed. Venus enslaved and bullied her ceaselessly, but Cupid’s love was undimmed.

Van Dyck shows Psyche’s final labour for Venus – to deliver a casket from the Underworld containing the secret of Proserpine’s beauty. Psyche disobeyed by opening the casket and Venus struck her insensate; the flourishing and the dead tree in the picture symbolise her living-dead state. Cupid arrived and saved her from the spell with his arrow.

In 1637, there was a recital at Charles I’s Court of Shackerley Marmion’s epic poem Cupid and Psyche. The story behind van Dyck’s picture would have been fresh in the memory of his regal audience: the lovers fled to Mount Olympus, where Jupiter sanctioned their marriage, Psyche was immortalised and they lived happily ever after. Love conquers all.

Van Dyck chose a scene to illustrate Plato’s definition of ideal love, ‘desire aroused by beauty’. As Court painter, he made several mythological pictures for the King. This is the only one known to have survived.