Outrageous review: This mediocre Mitford tale fails to tell us what was so Outrageous

Watching Outrageous (U&Drama, Thurs, 9pm), however, you can't really see why.

It's the story of the Mitford sisters, the famous – or infamous – sibling sorority that apparently took London society and the landed gentry by storm during the 1930s.

Each of the six sisters had some sort of celebrity: Nancy was a novelist, famed for The Pursuit of Love and Love in a Cold Climate; Diana was a famed beauty who left her fabulously wealthy husband for the country's leading far-right demagogue Oswald Mosley; Pamela was a noted horsewoman and fond of driving sports cars; Unity fell in love with Adolf Hitler; Jessica became a communist and ran off with her cousin; and Deborah became the Duchess of Devonshire and chatelaine of Chatsworth House.

Each had a notably picaresque life – even by the standards of the bohemian aristos of the time – with scandalous divorces, trips to the Nuremberg rallies, castles in Ireland and elopements to Spain – but very little of this comes across in Outrageous.

In fact, the most outrageous thing they seem to do is lounge about in silk kimonos and headscarves in the middle of the day.

We're supposed to care about these privileged creatures, but we're given precious little reason to. None seem particularly charismatic, especially given dialogue which attempts to cram in great chunks of exposition and quick character sketches as we meet yet another arrogant posho.

And why should we care about them, especially Diana and Unity, who didn't so much flirt with fascism as take it to bed for a night of passion.

At times, the programme attempts to give some reason for their lurch to the far right, such as widespread economic hardship and industrial unrest, but that rarely impinges on to the sisters' lives beyond a few banners in passing.

Diana is supposed to be infatuated with Mosley, but he comes across as a boring blowhard no one in their right mind would fancy, while Unity's obsession with Hitler is painted as a teenage crush.

I mean, these people weren't merely outrageous, they were just horrible anti-semites.

There is a charitable reading of all this putative outrageousness – that the sisters were kicking against the limited future societal norms had planned for them, as daughters of hard-up minor aristocracy.

Their mother, 'Muv' (Anna Chancellor) tells warring sisters Jessica and Unity: “Can't you see that if you don't start behaving properly you're going to end up as penniless old maids?

“You need to start thinking of yourselves as women. As wives and housekeepers, as mothers. These are incredibly important roles. Roles you were made for.

I guess faced with those constrictions, anyone with a modicum of gumption would attempt to kick over the traces.

But when financial hardship means 'letting out the London house', but still having a pied a terre in the capital, when no one seems to need a job, when you can live in varying degrees of bohemian luxury, rebellion seems unnecessary.

And far from taking a stand for women, these sisters seem unhealthily defined by the men in their lives – Diana by Mosley, Unity by Hitler, even firebrand Nancy moons over some weak-chinned deadbeat called Hamish, and Outrageous can offer no earthly reason for it.

If you didn't constantly refer to the internet, the average viewer – including me – would have very little clue why the Mitford clan should be so celebrated.

Far from being Outrageous, this latest ode to aristocracy is mediocre and, frankly, infuriating.