Last Night's Viewing: The Aristocrats, Channel 4 Falcón, Sky Atlantic

There's already a feature-length documentary called The Aristocrats, in which an array of comedians each deliver their personal rendition of an old and extremely dirty joke about incest, coprophilia and bestiality; the punchline is: "the Aristocrats". A prurient Channel 4 probably had this in mind when it commissioned and named its new series, about the large but mixed fortunes of Britain's remaining aristocratic families. The first episode promised much, but ultimately failed to muster any major family drama, let alone incest.

With 187 rooms, Blenheim Palace is the biggest in the UK: bigger than Buckingham Palace or Windsor Castle. It's home to the Dukes of Marlborough, the first of whom won the Battle of Blenheim and was awarded his prize – a vast stately home – by Queen Anne. But he fell out with the monarch, who forced him and his descendants to foot the bill for its upkeep. The present 11th Duke is a military man devoted to home and family. It was his idea to turn Blenheim into a tourist attraction, thus allowing the palace to pay its way.

His eldest son, Jamie Spencer-Churchill, Marquess of Blandford, is a Sandhurst reject, former drug addict and – if the programme's intro was to be believed – a bit of a useless git. The conscientious Duke did his best to disinherit the Marquess during the 1990s, but Jamie is now clean and living on the Blenheim estate, with the expectation that he'll take over when his father kicks the bucket. Any major decisions, though, will be subject to the agreement of a board of trustees, chaired by Jamie's younger brother, Edward, who wisely failed to take part in the documentary at all.

The programme-makers were granted less access than I suspect they'd have preferred, and resorted to what seemed like selective editing in order to portray Jamie as the feckless idiot they wanted him to be. The Duke's commitment to the local community was juxtaposed, for instance, with Jamie's plans for a water feature: "a HUGE fountain in the middle of the lake... Something ginormous!" In an attempt to inject some tension into proceedings, we also followed the weather-dogged construction of a new loo and gift shop.

Far more fascinating was the revelation, 22 minutes in, that the Duke had recently married his fourth wife, Lily, a rich Iranian. The first three were WH Smith heiress Susan Hornby, Jamie's mother; Athina Onassis, ex-wife of Aristotle; and Countess Rosita Douglas-Stjernorp, Edward's mother. Might this marital history have a part to play in the Duke's troubled relationship with his heir, not to mention the fraternal friction between James and Edward? The question was never asked, and Jamie and the Duke shared the screen for little more than a minute in the whole hour.

The show's juiciest moment did not concern the Spencer-Churchills at all, but their local MP, who came to officially open the new palace gift shop. The MP's minders would not allow him to be filmed in the presence of the aristocracy, so the programme-makers had to turn off their cameras. The constituency is Witney; the MP was David Cameron.

Sky Atlantic's new cop show, Falcón, also concerned itself with fathers and sons. Detective Javier Falcón was called in to investigate the brutal murder of a restaurateur, only to discover that the victim's history intersected with that of the late Falcón senior. A hefty budget and a lot of good actors have been thrown at this drama, including the fabulously brooding Marton Csokas in the title role. Falcón is based on the novels by Robert Wilson, and doubtless intended to rival the BBC's English-speaking Euro-cops Wallander and Zen. But the fine performers were let down by a bad story and a worse script. Wallander's misery is understandable: he inhabits bleak rural Sweden. But what's eating Falcón? He lives in Seville.

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