Patrick Stewart as Macbeth in a BBC production. ‘If Macbeth is a candidate for rehabilitation who next Rasputin (much maligned). Nero’ Photograph: BBC/Illuminations Media/THIRTEEN, Illuminations, BBC in

A well-read Scottish MSP, Alex Johnstone, has tabled a motion to the Scottish parliament to do one of those Richard III-style rehabilitation job on Macbeth. Shakespeare’s version Lies, all lies. If I read him correctly, Mr Johnstone goes as far as to fantasise a Macbeth theme park where the maligned monarch fell in battle.

It’s not recorded whether Mr Johnstone, just like the admirable Philippa Langley, has experienced a “trembling of the knees” treading at the monarch’s grave on Iona. And if Macbeth is a candidate for rehabilitation who next Rasputin (much maligned). Nero He’s had rather a foul press for the past 2,000 or so years.

In fact Richard III had more going for him than most stage villains relating to historical rehab. He’s disabled (amazingly, the skeleton proves it all the way down to the last vertebra). When Anthony Sher did Richard III he came on with such a lot of crutches he looked more like a walking prosthetics store than a monarch.

I fully expect, after what we’ve recently discovered, to live to work out a contemporary dress production of Richard III with the hero rolling on stage (“now could be the winter, etc etc”) in a motorised invalid carriage climaxing, at Bosworth, with the agonised “A go-kart! A go-kart! My kingdom for a go-kart”.

And there’s that picture of Richard inside the National Gallery, which – again amazing – is a spitting image of the hot forensic-lab reconstruction. Josephine Tey wrote an excellent novel about what’s to be deduced from that NG portrait, Daughter of Time (1951). Her detective hero, Alan Grant, a super “reader of faces”, takes one study it and concludes it isn’t the face of a mass murderer, but “a candidate for a gastric ulcer”. And, you may now add, a prolonged back-ache.

Back within the 11th century, royal portraiture hadn’t made the advances so brilliantly displayed in Paul Emsley’s recent depiction of the Duchess of Cambridge (no, i am not serious). What did Macbeth seem to be We’ll should dig up the skeleton and send the skull to the lab if we actually need to know. i do not believe Johnstone would wish that.

But does it matter If you would like history, visit the library or to Professor Google. If you wish drama, visit Shakespeare. It is not literature’s best kept secret that the playwright was dreadfully unfair in his depiction of the blood-drenched tyrant. He maligned Macbeth so one can butter up his patron King James. You do this variety of thing when you are the resident playwright of the King’s Players.

As a coolly informative BBC CV tells us, simply to take each of the fun out of the play, history was boringly different from what Shakespeare offers his audience. “Macbeth,” so it says, “was a king of the Scots whose rule was marked by efficient government and the promotion of Christianity.” Point taken, Mr Patten. But a play dedicated to the celebration of Scottish efficient governance (a topic dear to Mr Johnstone and his colleagues) does not, i believe, keep bums on seats till the fifth act.

I suspect however, that the motion to be brought before the Scottish parliament has subtler motives than just putting the record straight. Within the play, the English are Scotland’s friends in need. Malcolm recovers the throne through a Sassenach army. Macbeth, viewed objectively, is a persuasive plea for the union of both kingdoms (a sentiment which I, with as Scottish name as Mac Bethad mac Findláich, wholeheartedly share). It was for King James VI and that i, first sovereign of Scotland and England, that Shakespeare probably wrote his play (in huge haste, scholars theorise, for a state visit by the King of Denmark).

There are then, two reasons for continuing to honour Shakespeare’s version: it’s great drama and good politics. It’s horrible history, but so what