Jonathan Munby's production starring Ian McKellen, first seen last year in Chichester and now transferred to the West End, reflects our everyday anxieties, emphasising in the world of a Trump presidency, the dangers of childish, petulant authoritarianism. And while King James I was keen to promulgate the benefits of a united kingdom - having joined England and Scotland under his rule only three years before Shakespeare's tragedy was presented at court in 1606 - the corrosive nature of divisions within the state is equally clear now in the era of Brexit. The Union Flag features frequently in Paul Wills' design.

Munby is an inspiring director, especially of Shakespeare, mining text and motivation with meticulous care. His Globe productions of Antony and Cleopatra and The Merchant of Venice were especially revealing. Here, in a modern-dress setting, he makes much of the pagan nature of Lear as well as contemporary concerns. This places the action - clear and fast-paced though it is - in a strange world where people in combat gear pay deference to "the gods", showing respect for Apollo with ritualised hand gestures. 

If there are more ideas than the production's frame can easily contain, at its heart is Ian McKellen's mesmerising performance, exploring the vulnerability of old age, the absoluteness of death, the fragility of life and of sanity with such humanity, such a mixture of twinkling mischief, unforgivable cruelty, gentleness and sad acceptance of his failings that it takes your breath away. Much was made last year of the importance of the intimacy of the Minerva Theatre, which seats fewer than 300 people, but McKellen's performance remains unforced, even conversational, in its new surroundings. This is aided by the design, which includes a central walkway through the audience and a panelled wooden curve often limiting the stage area.

To begin with, Lear appears alone for a moment, enjoying the stage-managed surprise he is about to spring. His daughters sweep in dressed in ball gowns and the court sing together. All seems well-ordered, even good-natured, until the fateful fracturing of the kingdom. Sinéad Cusack plays good-hearted Kent, banished for speaking up and soon disguised as an Irish-accented male servant to the king in his homeless wanderings. The gender change makes perfect sense (as a similar casting, of Saskia Reeves did in Nancy Meckler's Globe production last year) and Cusack carries it off brilliantly.

Of the daughters, Anita-Joy Uwajeh as a strong-minded Cordelia and Claire Price as a Sloaney, pearls-and-headscarf, Goneril are new to the cast. Kirsty Bushell's fascinating Regan is unstable, kittenish, manipulative, sexually excited by the blinding of Gloucester. This is especially horrific, carried out with a meat hook in an abattoir. The heads of the dumb beasts - cow and pig - have already witnessed Lear's mock arraignment of his daughters.Lloyd Hutchinson's Irish Fool (above with Sinéad Cusack as Kent) plays the banjo and cheekily mimics his master - rather well. His witnessing of Gloucester's blinding and subsequent encounter with a murderous Edmund seem odd additions, however.

Danny Webb's Gloucester is a fine foil for McKellen and their Dover scene very moving as two old men, in the wisdom and foolishness of age, learn the error of their ways while facing mortality, one blind, the other madly wielding a bunch of weeds like a gun. Luke Thompson visibly grows up as Edgar and James Corrigan makes a clever, sardonic Edmund. But, however good the rest of the cast, it is McKellen who is unforgettable. His career has encompassed many of Shakespeare's major roles, including Edgar, Kent and, in Trevor Nunn's operatic 2007 RSC production, an earlier Lear. If, at 78, this really is his last stage performance in Shakespeare, it makes a stunning finale.

• King Lear at Duke of York's Theatre to 3 November 
• Read more theatre reviews on theartsdesk

@heathermneill

Overleaf: more great Lears

Mamma Mia! has a habit of bursting upon us at crucially restorative moments. The Broadway production opened just after 9/11 and provided necessary balm to a city in shock. Now comes the celluloid prequel of sorts and, lo and behold, what could have been merely a crassly commercial exercise has exactly the right innocence and heart to act as a giddy summer corrective to our coarsened times.

Aidan Turner may not reveal those famously bronzed pecs that have made TV's Poldark box office catnip in his West End debut. But what Michael Grandage's funny and fiery revival of The Lieutenant of Inishmore reveals in spades is the irresistible charisma and stage savvy of an actor fully at home in what can only be called Martin McDonagh-land.

History repeats itself. This much we know. In the 1980s, under a Tory government obsessed with cuts, the big new thing was “event theatre”, huge shows that amazed audiences because of their epic qualities and marathon slog. A good example is David Edgar’s The Life and Adventures of Nicholas Nickleby, an eight-and-a-half hour adaptation of the Dickens novel.

Shall we dodge? (One, two, three) No, the brilliance of Bartlett Sher’s Tony-winning Lincoln Center revival – first on Broadway in 2015, now gracing the West End, with its original leads – is that it faces the problematic elements of Rodgers and Hammerstein’s 1951 musical head on.

Question: is Consent, transferred from the National to the West End, a sharp-tongued comedy or an acute reinvention of a revenge drama? There are more than enough smartly placed laughs throughout the tart, increasingly taut first act, to make you think you’re watching an amusingly balanced, if increasingly vicious, exposé of the divide between the private and professional lives of lawyers.

The band’s back together. Alfred Molina plays Rothko for the third time in Michael Grandage’s revisiting of John Logan’s richly textured two-hander, first seen at the Donmar in 2009 and then bypassing the West End for Broadway.

Back by feverishly popular demand, Jim Steinman’s mega-musical is no longer in danger of alarming unsuspecting opera-goers. A year on from its Coliseum debut, this indisputably bonkers show moves to the West End venue it was surely always destined for – that lingeringly inhabited by its rock operatic forebear.

It is, perhaps, a tale that suffers from overfamiliarity. Tina Turner’s rags-to-riches story – from humble beginnings as little Anna Mae Bullock in Nutbush, Tennessee, to her discovery, reinvention and sickening abuse by husband and manager Ike Turner, and finally her rebirth as a solo rock'n'roll star – is the stuff of showbiz legend.

You could be forgiven for not remembering the “coughing major” brouhaha in 2001, coming as it did the day before 9/11, when we had rather more pressing matters to attend to than a contestant being accused of cheating on television quiz show. But playwright James Graham has mined an entertaining confection from the affair and its subsequent court case in 2003.