Does Milly Alcock find her characters inside herself or does she sketch them from outside? ‘It’s both,’ she says. ‘You know if you ask someone to draw an apple they have to know what an apple looks like but you put your own spin on it, you have your own understanding of who this person is and you may know someone who’s similar to them but they don’t do it out of thin air because you have to make choices.’ Milly Alcock has just been seen as Princess Rhaenyra Targaryen in House of the Dragon and from 15 November you’ll be able to see her in Season 2 of Upright the extraordinary comedy/drama she did with Tim Minchin and the range displayed between the cutglass Princess of the Dragon World and the raucous Aussie chick is extraordinary.

Tim Minchin can’t speak too highly of her and he’s a man whose career encompasses worlds. He talks dryly about people who ‘want to atone for all the sins of history’ and the way lefties like himself ‘exhibit self-justification bias’ and he groans at the idea of putting ‘politics before art’. He’s exhilarated by the new film of his Roald Dahl show Matilda the Musical with Emma Thompson as Miss Trunchbull. He says, ‘Miss Trunchbull is a monster in the Scandinavian, Dalian sense. She’s a towering mesomorph.’ And he has a reverence for Milly Alcock’s talent. Minchin agrees with his friend Richard Dawkins, he’s a materialist and an atheist, but he can’t come at Dawkins sneering at something like Dante’s line ‘The love that moves the sun and other stars.’ He’s one of those prodigiously talented people who’s almost jumping out of his skin with ambition and he wrote the Olivier Award winning-musical Groundhog Day for precisely his own kind of introspective auteurship but he is loath to perform it on stage himself because he hates the idea of being stuck in any show for any period of time.

Would Claire Foy have been driven mad if she had played the Queen in perpetuity rather than just the first two seasons of The Crown? Season 5 is upon us now. It’s worth remembering that what lies behind Peter Morgan’s immensely successful series is the script he wrote for Stephen Frears’ The Queen. And the glory of that film was Helen Mirren’s superb performance – her reincarnation of the Queen – at the time of Diana’s death. Season 5 of The Crown doesn’t carry us that far but the ten hours of it make it abundantly clear that the star performance here is from Australia’s Elizabeth Debicki as Diana.

She turns her head in that characteristic gesture on one side, her eyes fill with a steady wonder and a conscious charm but she also has exactly the right sense of fun. She exhibits with a dazzling exactitude Diana’s dizzying emotional intelligence – she was not the queen of hearts for nothing – and she captures the in-built peril of the fact that Diana’s emotional intelligence was at the expense of every other kind. To give far and away the finest performance in Season 5 of The Crown in a company that boasts Imelda Staunton – Elijah Moshinsky said her performance in Gyspy was one of the greatest he’d seen – as the Queen together with Lesley Manville as the older Princess Margaret, Olivia Williams as Camilla and Dominic West as Prince Charles is to outshine the best of British.

It’s an odd compulsion, The Crown, because it’s such a lustrous supersoap. Imelda Staunton equals Olivia Coleman’s Queen in the previous seasons but does not surpass her and neither of them – great actresses though they are – have the magnetism, the star quality of Claire Foy or indeed Helen Mirren. It’s not hard to see why Helen Mirren should have backed away from the role of playing the mature Queen again as a kind of James Bond stereotype but it’s a pity not to have her. Perhaps they should have offered the role to Emma Thompson.

As things stand it’s a mixed bag. That marvellous actor Jonathan Pryce has none of the hawk-like hauteur we associate with Prince Philip and Dominic West is like a transfiguration of Prince Charles. He’s such a magnetic leading man but he does do something with his voice that creates a resemblance.

There are various attempts to open things up. Lots of Arabic in the scene that introduces Mohamed Al-Fayed, a flashback to Alex Jennings as the Duke of Windsor demonstrating what born-to-rule charisma is like. There’s a whole episode about the Romanovs with a Boris Yeltsin look-alike and the Queen herself demonstrating slightly improbable astuteness about Queen Mary’s rejection of asylum for the Tsar’s family.

One of the finest moments and the least expected is when Lesley Manville’s Princess Margaret reproaches her sister for not letting her marry Peter Townsend. We’ve seen her meet Townsend – played vividly and vivaciously by Timothy Dalton – but Margaret tells her sister how she broke her heart. Manville is thought of as a Mike Leigh actress with a hard-faced toughness but she has a pretty extraordinary poignancy in this scene and Staunton rises to meet her.

Where does all this leave Judi Dench’s objections to the continuation of The Crown coming as it does so close on the heels of the Queen’s death? Was it bound to seem a bit icky? Perhaps. But it’s worth remembering that Her Majesty is said to have liked the show and that history begins as a story we imagine. Gore Vidal – talented novelist and sublime essayist – was a friend of both Princess Margaret and President John F. Kennedy. Some of the stories he tells in his dazzling memoir Palimpsest are just a bit good to be true.

Should this worry us? Not overwhelmingly. The historical material that lies behind The Crown is sometimes a matter of record and sometimes a matter of dramatic reconstruction or readjustment. But any young person will feel the impact of history as well as gossip.

And Diana, poor tragic woman, took the celebrity aspect of regality to its logical conclusion and Elizabeth Debicki captures this with a stunning brilliance. It’s a long way from Milly Alcock as Dragon Princess or Aussie wild girl but they share a lustre and a starriness that is blinding.