The great moment had come. In one of the state rooms of Buckingham Palace, the King reached out and pulled the red tag in the centre of an enormous black cloth. A moment later, the cloth fell away and his guests burst into applause. A portrait that had taken three years was finally revealed. And it was red - very red.

Larger than life size, the painting is by Jonathan Yeo - a hugely experienced portrait artist whose previous subjects have included Tony BlairTony Blair was the leader of the Labour party. He was British prime minister from 1997 to 2007. , David AttenboroughAn English broadcaster and natural historian known for his wildlife documentaries. and Malala YousafzaiA Pakistani activist for female education and the youngest person ever to win the Nobel Peace Prize. In 2012, aged 15, she was shot by the Taliban. . It shows Charles in the uniform of the Welsh Guards, of which he is the regimental colonel, leaning on his sword. The uniform is red and so is the swirling background.

According to Yeo, the King "was initially mildly surprised by the strong colour", but seemed to approve of it.¹ Queen Camilla told the artist: "Yes, you've got him."

There is a long tradition of painting monarchs in military uniform. But this portrait has an unexpected detail. As Yeo explains:

"I said: 'When schoolchildren are looking at this in 200 years and they're looking at the who's who of the monarchs, what clues can you give them?' He said: 'What about a butterfly landing on my shoulder?'" The creature a clearly a reference to Charles's concern for the environment.

Some great portraits survive of previous monarchs. One is the "ArmadaA fleet of warships. portrait" of Queen Elizabeth IThe Tudor Queen of England from 1558 to 1603., attributed to George Gower. She wears a huge number of white pearls, which are associated with the Virgin Mary, with a black dress and cloak symbolising constancy. Through a window in the background we can see the storm which scattered the Spanish ArmadaThe Spanish Armada was a Spanish fleet of ships that sailed from Lisbon to England in late May 1588, with the intention of attacking the English navy..

Another is Hans Holbein the Younger's portrait of Henry VIIIThe King of England from 1509 to 1547, best known for his six wives. . According to Britannica: "Henry's flat face and small, wary eyes realistically depict his unique character, while his magnificent apparelClothing of a particular kind.... elaborates on his regal authority."

Anthony van Dyck painted Charles IThe king who sparked the Wars of the Three Kingdoms, which included the English Civil War. He was accused of tyranny by Parliament and ended up being executed for it. on horseback for a portrait 12ft high. His melancholy expression is seen as a sign of wisdom.

Not all royal portraits have been well received. Some people said that Lucian FreudA British painter who was the grandson of Sigmund Freud. In 2015 his painting The Brigadier was sold for £35.8m.'s portrayal of Queen Elizabeth II made her look like a rugby player, or else one of her own corgis.²

And according to Alastair Sooke in the Daily Telegraph, the new portrait shows a King "who, while kindly, and despite his military garb, isn't entirely sure of himself". Sooke nicknames him Charles the Unsteady.

This is some of the symbolism that can be found in the portrait:

Swirling colours Create a sense of turbulence, reflecting the recent upheavals both in the royal family and in world politics.

Background match The fact that his uniform is the same colour as the background indicates that even though he looks confident, he is caught up in the surrounding whirlwind.

Fluttering butterfly Symbolises not only his love of nature and devotion to conservation, but his metamorphosisA complete transformation or change of appearance and structure.  from prince to king.

Sword stance Having his hands resting on his sword gives a sense of steadfastness amidst the chaos.

Is this Charles the Unsteady?

Yes: It is a far cry from traditional royal portraits such as Elizabeth I's, where the subject stands out clearly from the background and appears to be very much in command of the situation.

No: His subtle yet confident expression conveys the King's enduring presence. He had to stand still for 40 minutes at a time in the heavy uniform to pose for the portrait, but managed to remain cheerful. 

Or... He could not be blamed if he were unsteady, since he was diagnosed with cancer while it was being painted. Yeo says the portrait shows exactly who Charles is, "everything he represents and what he's been through".