Titian by numbers: What our £50m bought

After years in private hands, 'Diana and Actaeon' has been saved for the nation. Michael Glover decodes the symbolism, style and story of a Renaissance treasure

(National Galleries of Scotland/PA)

1. Titian's palette, as always in his work, is rich, dazzling and various. He paints subtly, but also with great forcefulness. He seems to be engaged in one-to-one combat with the canvas. His brush marks are feverish. He pushes his brush about the surface of the painting – dabbing here, smearing there, pushing and pulling. The scene itself is an agitated one – and that's also a very good way to describe the way he paints it.

2. This is a natural scene, which is shot through with sheer artifice. The gods exist, powerfully, in their own imaginary worlds. We dip into that, embrace it – rather in the way that we suspend disbelief when we go to the theatre. It is then perhaps unsurprising that the entire scene – nympths, huntsman, grotto and all the gorgeous trappings – looks exactly like a beautifully crafted theatre set.

3. Look at the grotto itself in which the scene is set. According to the words of Ovid, "nature by her own devices had imitated art" in the creation of Diana's cave, and had 'carved a natural arch from the living stone and soft tufa rocks'. Titian is very careful to suggest this combination of the natural and the artificial. The gothic vaulting, for example, seems to branch up like the trees which envelop it.

4. We are in Diana's grotto. Look at the ram's skull which is poised above the nymphs as if observing the scene, its skeletal snout resting on a corbel. This is an ominous detail, indicative of death itself, and how it looms over all of us, and of the tragic future of Actaeon himself, who will be transformed into a stag by the vengeful goddess whose privacy has been violated, and torn to shreds by his own slavering hounds.

5. There is a subtle kind of anthropomorphism at work here – in the way in which Titian has painted the trees, for example, cleverly intermingling them with the Gothic stone arches. They seem to be enclosing the grotto, all leaning down and huddling together, as if to ensure that this grotto will be the goddess' private space, wholly set apart from the world – until, that is, the world bursts in – in the form of a burly young huntsman.

6. Look, too, at the crescent moon which forms a significant part of the adornments to Diana's hair. In this scene, Diana looks every inch the voluptuous young maid, but in fact she is hugely significant in classical mythology, and the presence of the moon reminds us of this fact. Diana herself is the chaste goodness of the moon, that "queen and huntress chaste and fair" of which the English poet speaks. All the more terrible then for her gentle ablutions to be interrupted in this way by a mere hunstsman.

7. The scene itself, a very familiar one, derives from the Roman poet Ovid, and it is one of sudden, arrested action. See how Diana, seated amongst her nymphs, recoils, raising her left arm in anger and horror at the young huntsman's appearance in front of her, and how Actaeon himself raises his left arm, as if in acknowledgement that he has violated her privacy.

8. Everywhere here there is a sense of hurry and tumult. Eight figures in all – plus one dog - are vying for our attention. Notice how Titian has increased the size of Diana relative to her nymphs, all the better to single out the fact that it is her murderous glance which will settle the fate of the huntsman, and that it is her gorgeously voluptuous body which has been violated by the male gaze.

9. In his mythological scenes , Titian was a great painter of physical turbulence – everywhere in his paintings there are violent acts going on, lungings, twistings, swervings. One tiny detail in this painting seems to summarise the whole of that side of Titian's personality – the way, when Actaeon bursts in from stage left, his huntsman's short skirt seems to be almost blowing in ahead of him. Everything happens in an almighty rush.

10. Titian tells this segment of the story in full knowledge that those who will be looking at this painting at the court of Philip of Spain will be very familiar with its least detail, and what it signifies. The water at Diana's feet, for example, will call to mind the fact that when Diana comes to take her revenge upon the young huntsman who has strayed into her grotto, she will splash water into his face – this act will lead directly to his destruction by those ravening dogs.

11. Look at the gorgeous velvet stuff on which Diana sits, crushing it beneath her comely buttocks, and how it seems to rhyme visually with the other drape which hangs, suspended from a cord, with such seeming casualness, directly behind Actaeon himself. These drapes enable Titian to show off his colouristic brilliance, rendering the scene all the richer and more sensual.

12. Small dogs are very conspicuous in paintings of the Dutch Golden Age, adding to the anecdotal vitality of many indoors scenes. Here the small ferociously yapping dog plays a more important role. It knows, almost instinctively, that Actaeon has violated Diana's space. Its presence here seems also to be a reminder of the fact that it will be dogs in the end which will bring about his death.

Diana and Actaeon is on display at the National Gallery of Scotland, Edinburgh. In September it moves to the National Gallery in London