The Weekend's TV: The Genius of British Art, Sun, Channel 4<br/>When Piers Met Lord Sugar, Sat, ITV1

"The Tudors invented the portrait," said David Starkey in The Genius of British Art. "Eh?" I thought. Come again, Dr Starkey?

I know you're passionate about the period but that's a tiny bit of a stretch, isn't it? Next thing you'll be telling us that they invented eggs and the rubber band. But I had interrupted too soon it seems, because Dr Starkey hadn't finished with his sentence. "And the portrait in turn gives us our idea of the Tudors," he concluded. The thought briefly occurred that the first half of this sentence (tendentious to the point of barminess) was only there to dress up the second half (self-evident to the point of banality). But then I got distracted by Henry VIII's armour, called in evidence by Dr Starkey as a hammered-steel affidavit for the accuracy of Holbein's portrait. To be fair, Dr Starkey has his powers of distraction too, and he drew us close in at this point for an anecdote about his one- time mentor, the Tudor historian G R Elton. Not a big man for visual aids, Professor Elton, but apparently he did have one lecture-hall party trick, when he would draw a simplified, stick-figure rendering of the famous portrait of Henry standing, legs apart, like a bouncer bracing for trouble. Dr Starkey replicated it, too, to show us the geometrical solidity of the image Holbein had created and make a slightly tenuous link between this masterpiece of the Northern Renaissance and agitprop posters of Marx and Lenin.

The connection wasn't anything like as fragile with the next portrait he looked at in detail – that which appeared on the title page of the Great Bible, distributed to every parish by royal decree and bearing the wildly presumptuous image of Jesus Christ handing down the scriptures to Henry VIII, so that he could pass them on to his loyal subjects. Jesus looks a little like a civil servant in this picture, hovering tactfully behind Henry's shoulder so that he can hand over the paperwork at the appropriate moment. Every bit of power resides in the big man. That was the essence of Starkey's opening contribution to Channel 4's series of "polemical essays" about British art – the notion that official state portraits are designed to enhance the authority and status of the sitters, and while that fairly obvious statement might not strike you as the stuff of polemic, it was done with reasonable flair, taking us from Holbein's power-projection to Diana, Princess of Wales's artful use of vulnerability. Starkey presented her as an instinctive master of media manipulation, crafting her photo-opportunities to conjure into being the sympathetic words she wanted printed underneath them. I'm not sure that he fully took into account the extent to which she was fitting into a template that the tabloid press had designed for her, but it was intriguing nonetheless to think about how the command of public loyalty eventually came down to the question of who could look most fetchingly pitiable.

The Tudors had Holbein. We get Piers Morgan, who from time to time will pitch up at the doors of the rich and famous to craft a flattering portrait. It will be ornamented with emblems of their wealth and success and it will use as its principal medium the bantering interrogation – the vanity of the famously portrayable now being centred on their ordinary human approachability, paradoxically conveyed to us by a form (the exclusive-access documentary) that simultaneously underlines their apartness. "None of us know the real man behind the persona – until now," boasted the voiceover at the beginning, which is fairly reliable sign that a bit of persona engineering is about to take place. In the case of Saturday night's programme – When Piers Met Lord Sugar – it was Britain's favourite entrepreneur attempting to show that he isn't a grumpy monster after all, but actually an affable, avuncular figure with an unexpected taste for road bikes and Lycra cycling gear.

I gritted my teeth for this one, because of Morgan rather than Sugar, who appears to combine a touching pride in his social elevation (there were pictures of him with the Queen in virtually every room) with a refreshing indifference to public opinion. But – though this too emerges through gritted teeth – Morgan was actually not bad at all, teasing his subject in ways that at least tested his good temper. "Sort of thing I'd expect to find in Elton John's house," Morgan said pointedly, when he came across a flamboyantly camp pair of mirrored statues in the Sugar dining room. I don't think there were any huge revelations, particularly for Sugar addicts who've already read the autobiography. But those who haven't may have been surprised by how candid Sugar was about the ways in which his parents had failed him, and how, in return, he had failed his mother. He may be a driven man, but you sense that, these days at least, he's in the driving seat, confident enough to know that an acknowledgement of weakness isn't weak itself. It's almost unthinkable I know, but might he have talked these things through with a professional? He joked at the end about taking a psychology course and starting a new business: "How about Ampsych – I could do discount. Thirty minutes' analysis for £39 quid." "Your only advice would be the same for everyone," Morgan replied. "Get over it." His Lordship laughed a lot at that, and he wasn't just faking it to be polite.

t.sutcliffe@independent.co.uk