He may not have been an ideal ruler but, as a new exhibition shows, he had great taste in art

In 1623 Charles Stuart, heir to the thrones of England, Scotland and Ireland, travelled to Madrid to woo the daughter of Philip III of Spain. His bid to win her hand in marriage failed, and the abortive “Spanish Match” ended in a romantic and diplomatic mess. But if the trip left the young prince disenchanted with courtship, it did stir another passion – his love of art. Overawed by the splendours of the Habsburg court, Charles resolved to build a collection worthy of comparison. He left with a clutch of artworks including a Veronese, a Giambologna and several Titians.

Over the following 25 years, Charles I (he became king in 1625) amassed an extraordinary collection. Aided by his wife (for he did get married in the end, to Henrietta Maria of France) and well-connected connoisseurs, he bought, commissioned and was given works from across Europe. Leading artists came to London at his invitation – Orazio Gentileschi arrived in 1626, Rubens in 1630, Van Dyck in 1632 – and in 1628 he acquired the entire Gonzaga collection, a trove of paintings and classical sculpture, from the Duke of Mantua. Fine tapestries were woven at the Mortlake Tapestry Workshop, while a few miles downriver, Whitehall Palace was filled with a dazzling array of artworks intended to assert the magnificence of Charles’s reign – even as social unrest, then civil war, rocked his kingdom.

In January 1649, Charles was executed and the majority of his collection sold off. Much was recovered after the Restoration, but many pieces remain scattered around the world, and some have disappeared altogether, lost or destroyed. For the next few months, however, visitors to the Royal Academy in London can see the best part of it reunited for an impressive exhibition, “Charles I: King and Collector”.

The most striking aspect of this display is the quality. Masterpieces abound, from Holbein’s sober portraits to the sensuous allegories of Titian, Correggio and other Italians. Entire galleries are given over to monumental decorative schemes, including a series of tapestries made after designs by Raphael at the Mortlake Tapestry Workshop; another room is devoted to prints, miniature portraits, medallions and other small treasures that were housed in Charles’s private quarters. And then there are Van Dyck’s sumptuous portraits of the king and his family, intended to shape his public image as a cultivated and powerful European ruler.

But the exhibition is also remarkable for its portrayal of collectors, and collecting. We learn, for example, about Abraham Van der Doort, Surveyor of the King’s Pictures, who had the formidable task of cataloguing the Whitehall Palace holdings; a working copy of his lengthy inventory is on display. Records from the sale of Charles’s collection reveal which artists were most sought-after at the time, with a few surprises (Italian painters like Guido Reni, whose work must have seemed excessively sensuous to Puritan sensibilities, was highly valued). Combined, these accounts and the splendid exhibits reveal both the grandeur and the intricacies of Charles I’s ill-fated court.

“Charles I in Three Positions” (1635–36) by Anthony van Dyck

In 1636, Charles and Henrietta Maria commissioned a bust of the king from Gianlorenzo Bernini, a celebrated Italian sculptor. To give him something to work from in Rome – and to indicate the quality of work that they expected – they sent him this triple portrait by the “principalle Paynter in Ordenarie to their Majesties”, Anthony van Dyck. Bernini’s bust was duly completed and shipped to England, to the delight of the royal couple. Sadly, the sculpture was destroyed in a fire that swept through Whitehall in 1698 – but a related bust by Francois Dieussart, which was probably made with reference to the same painting, survives and greets visitors to the exhibition.

Van Dyck’s painting is a masterpiece of its own. He added more nuance than was required and expertly captured details – such as the king’s reddened knuckles and shadowy veins – that Bernini could not have hoped to emulate in marble. Seen together, the two works would have been a fascinating example of rivalry and dialogue between two artists at the top of their game.

“Aphrodite (‘The Crouching Venus’)” (second century AD )

The beautiful figure of Venus, goddess of love, has always been a popular subject for artists, and there were many depictions of her in Charles’s collection. This is one of the oldest, an ancient Roman copy of a Greek original showing the goddess, having been interrupted while bathing, rushing to cover herself. Daniel Nijs, the Flemish merchant who negotiated the sale of the Gonzaga collection, to which this work belonged, described it as “the most beautiful of all” the ancient sculptures in the group, and Rubens was also an admirer: he saw the work when it was still in Mantua, and the figures in several of his paintings echo its pose.

“Venus with Mercury and Cupid (‘The School of Love’)” (c. 1525) by Correggio

In this serene yet sensuous painting, Venus looks on as Mercury, god of wisdom, gives a lesson to their son Cupid. The figures stand close together, indicating their intimacy, and Correggio’s smooth handling of the paint lends the scene a soft-focus atmosphere. The artist has paid attention to detail, capturing the child’s glossy blonde curls, the shifting colours in his feathered wings, and the rough twine securing Mercury’s sandals. This piece was also acquired as part of the Gonzaga collection, along with its pair, “Venus and Cupid with a Satyr” – a less salubrious work in which the sleeping, naked goddess is ogled by passing satyrs. In the 17th century, paintings by Correggio were extremely sought-after. This example fetched one of the highest prices in the sale of Charles’s collection: £800.

“Anne Cresacre” (c. 1526–27) by Hans Holbein the Younger

Hans Holbein the Younger did as much to shape the image of the English court in his day as Van Dyck did a century later. This drawing of Anne Cresacre, a noblewoman, was a study for his first major commission in the country, a large family group portrait, which has subsequently been lost. Holbein has skilfully recorded not just her features, but her expression: she looks distractedly out into the distance, her brow slightly furrowed. With just a few lines, he has also captured the sheen on her dress, while bold, yellow highlights indicate its brighter trimmings. Charles inherited a portfolio of Holbein drawings from his older brother, Henry, who died of typhoid fever in 1612. But the young king preferred Italian art, and in 1627 or 1628, he gave them to Philip Herbert, 4th Earl of Pembroke, in exchange for a Raphael painting of “St George and the Dragon”.

“The Triumph of Caesar: The Vase Bearers” (c. 1485–1506) by Andrea Mantegna

This is one of nine monumental canvases in a celebrated series by Andrea Mantegna, an Italian Renaissance artist. Each painting depicts a different part of an imagined parade in honour of Julius Caesar. In this, the fourth section, the central figure carries a hefty vase which he steadies with a sling. Mantegna’s depiction of the polished, colourful stone is masterful, and in the background he has painted tiny details of rural life. Trailing behind the vase bearers, in the following canvas, is a troupe of elephants, with Caesar himself bringing up the rear on his chariot, resplendent in gold robes and crowned by the winged figure of Victory.

These paintings were the last to be consigned from the Gonzaga collection, and the Duke of Mantua parted with them reluctantly (he was seriously strapped for cash). The series was singled out for praise in Vasari’s influential “Lives of the Artists” and was widely celebrated as a symbol of wealth, leadership and royal authority. Charles must have enjoyed the connection with the illustrious Roman leader. What he could not know was that Caesar's story also foreshadowed his own grisly end.

Charles I: King and Collector Royal Academy, London, until April 15th