As Oscar season hots up, the frontrunner in several categories is The Favourite, Yorgos Lanthimos’s marvellously mad film about jostling for power in Queen Anne’s court. The film’s success represents Olivia Colman’s elevation to the highest echelons of the movie hierarchy, but if it wins big on 24 February it will also mean a return to favour for a genre largely ignored by the Academy in recent years: the period drama.

Back in the olden days – say, the mid-1990s – period dramas were the perfect career move for actors who feared a fluffy romcom might be too risque. Many actors established their Oscar calibre with an Austen adaptation (Gwyneth Paltrow, Keira Knightley, Kate Winslet), a Merchant Ivory production (Helena Bonham Carter, Hugh Grant, Daniel Day-Lewis) or royal biopic (Cate Blanchett). Meanwhile, at the box office, these films have been the meat and potatoes of British film – reliable, traditional, unexciting – for about as long as the industry has existed. Then, about 10 years ago, period dramas started getting weird – very weird. Screaming the F-word at a string quartet from a palace window weird, or holding a catered birthday party for your 17 bunny-babies weird.

While Lanthimos is about to get the glory, this tone-change was pioneered mostly by a handful of female directors. Period drama had always been unusually interested in women’s inner lives, but films such as Sofia Coppola’s post-punk Marie Antoinette (2006), Jane Campion’s dreamy Keats biopic Bright Star (2009) and Andrea Arnold’s influential Wuthering Heights (2011) took that further. They eschewed the conventions that had long defined the genre in pursuit of a more direct expression of characters’ thoughts and feelings.

Often this involved a rejection of the traditional trappings of romantic drama, as in the 2014 Austrian film Amour Fou, which recounts the real-life story of the suicide pact (or murder-suicide) of 19th-century German poet Heinrich von Kleist and his lover Henriette Vogel. In writer-director Jessica Hausner’s deadpan telling, there’s no mistaking the vanity that motivates Heinrich’s supposedly grand, romantic gesture.

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And if you were shocked by The Favourite’s fruity language, then you must have missed 2016’s Lady Macbeth, a pared-back adaptation of Nikolai Leskov’s 1865 novella, relocated to 19th-century Northumberland, in which a stifled young bride (played by Florence Pugh) rails against her oppression with murderous consequences. In it, director William Oldroyd replaced the usual chaperoned tea parties, averted gazes and stuttering proposals with a different kind of courtship ritual. That is, if you can call the rutting that unites Florence Pugh’s character and a local farmhand “courtship”.

It annoys historians, but laypeople do continue to derive their impressions about the past largely from film and television drama. This can mean that when we watch a historical film we’re not seeing an accurate depiction of times gone by, nor even a film-maker’s take on times gone by; we’re watching a film-maker’s take on films gone by.

The period dramas that attempt to disrupt that misinformation cycle do so partly by depicting the grubby texture of everyday life before the advent of antibiotics and washing detergent. So, when the words “This Mud Stinks” appear on screen in The Favourite, it’s as much a mission statement as it is a chapter heading: period dramas are to be defined by frilliness and formality no longer. Accuracy per se isn’t the goal; as co-screenwriter Tony McNamara told the LA Times: “No one knows how anyone spoke back then. That was the thing about the dialogue – I don’t know how they spoke, so it doesn’t matter to me how they spoke. I wasn’t trying to mimic something. It’s how I imagined they would speak. And most of all, we wanted it to be funny.”

That said, the effect of this explicitness isn’t merely to make the films more relevant for contemporary audiences. In the case of The Favourite’s lesbian love triangle, at least, there is also some factual basis. “What I can tell you is that people at the time thought that Queen Anne and the Duchess of Marlborough were [lovers] and this was a line of attack that was used by their political enemies, so that’s one thing,” says historian Lucy Worsley, who is curating an exhibition of The Favourite’s Oscar-nominated costumes at Kensington Palace and Hampton Court Palace. “Another thing is that people were very much sharing beds the whole time; that was a standard way of sleeping. So who knows when they were and when they weren’t having sex? It’s all very difficult to define, isn’t it?” she says. “I sound like a millennial!”

Millennial trendiness might also be detected in another characteristic aspect of the new period drama: their increasingly diverse casting. This challenge to Hollywood’s long-entrenched habit of whitewashing history is, however, overdue. In his barnstorming speech on diversity at the 2016 London film festival, Selma star David Oyelowo described the difficulty he had getting a biopic of the black, 19th-century, bare-knuckle boxer Bill Richmond into production. One rejection letter summed up the limiting view of the time – that British period drama should offer viewers a “treat” by depicting “either a familiar title or a piece of history which is ripe for a revisit”.

Oyelowo’s project is yet to be greenlit, but in the meantime Mary Queen of Scots and Lady Macbeth feature roles for black British actors, and 2018’s Victoria & Abdul joined Amma Asante’s 2013 film Belle on the shortlist of British period dramas with non-white leads. This, too, can be justified by historical record (Onyeka’s book Blackamoores documents a significant presence of dark-skinned people in Tudor England, for example), but as Worsley points out, that’s rather missing the point: “Feature films are not accurate historical sources – it’s a very common misconception – but they are entertainment. They are not a guide to the past. They’re a source of wisdom rather than knowledge, and they’re about emotion rather than fact.”

Perhaps it’s no coincidence, then, that the emergence of new period drama roughly coincides with an explosion of academic interest in the history of emotion, a research field that Worsley enthusiastically describes as “what all the cool-kid historians are working on”. The website for the 2008-founded Centre for the History of Emotions at the Max Planck Institute in Berlin describes their work as resting “on the assumption that emotions – feelings and their expressions – are shaped by culture and learnt in social contexts … [and are] thus historically variable and open to change”.

Is the experience of a young queen trying to establish her authority hundreds of years ago comparable to the plight of a 21st-century leader? Did love feel the same in Tudor England as it does today? What about lust? Or grief? And how can these emotions be translated from one era to another, if at all? The answers are as varied as the films, but one thing is obvious: in all its sweary, smutty, oddball glory, period drama is now far from cinema’s safe bet – and all the better for it.