As she became the longest-serving monarch in British history last year, Queen Elizabeth marked a reign that has stretched through seven decades and 13 British prime ministers — and counting.

The monarch's relationship with those men and women is the focus of The Audience​, a 2013 play by Peter Morgan (revised in 2015 to include then-topical events involving David Cameron, but too early to include current PM Theresa May).

Morgan's play gets its Canadian premiere in this co-production of Toronto's Mirvish Productions and the Manitoba Theatre Centre — designated "royal" by Elizabeth herself in 2010. In it, we see a series of the weekly meetings between the Queen (stage veteran Fiona Reid) and her PMs, from Winston Churchill (played solidly, but not slavishly, by John B. Lowe) to Cameron (a stoutly British Ben Carlson).

Major and Elizabeth in The Audience

While there's an underlying sadness in The Audience, it also highlights the Queen's sharp wit, particularly in a scene with John Major (Evan Buliung). (Dylan Hewlett)

Those looking for deep insight into and detailed biography of Elizabeth will need to look elsewhere (perhaps at the 2006 film The Queen, for which Morgan wrote the screenplay, or the current Netflix hit The Crown, which he created).

The Audience is less a biography of the monarch or her prime ministers than it is a contemplation of a constitutional monarchy, and how it — and its monarch — endure. Through the Queen's audiences, we see the unique relationship between head of state and elected leader unfold, as Elizabeth deftly attempts to advise without giving advice and support without directing.

If that sounds a bit stuffy … well, sometimes it is. The Audience, a Broadway hit (thanks in large part to a Tony Award-winning turn by Helen Mirren in the lead role), is not a perfect play. Its episodic nature means it never develops a strong narrative through line, and many of its characters appear so briefly as to seem more dramatic devices than relatable people.

But where The Audience works, it works beautifully — and it's in the scenes, not coincidentally, that show the most passion. Take, for instance, the exchange between Elizabeth and Margaret Thatcher (a believably no-nonsense Kate Hennig), which is all skillfully restrained aggression and cold fire.

Fiona Reid in The Audience

Fiona Reid has the daunting task of playing the monarch over a span of decades, and delivers a graceful performance that anchors the production. (Dylan Hewlett)

But the centrepiece are the scenes involving Harold Wilson (an effortlessly charismatic Nigel Bennett), the Labour prime minister in the '60s and mid-'70s. As his initial resistance to the "posh" monarch dissolves, and Elizabeth warms to the comparatively rough-spun PM, we see some of the person behind the figurehead — and the type of friendship she's denied.

And for all its considerable humour, there's an underlying sadness to The Audience. There's plenty of the former, from the awkwardness of Evan Buliung's desperately unhappy John Major to many snappy one-liners from the monarch herself. (Take, for example, Major's complaint that "I only ever wanted to be ordinary," and Elizabeth's reply, "And in which way do you consider you've failed in that ambition?")

But the sadness is that Elizabeth will endure, as the monarch and the monarchy must — watching others enter and leave her orbit (whether she likes them or not) through intimate meetings that must remain detached yet friendly, but not the basis of any real friendship.

That theme is underscored through conversations Elizabeth has with her younger self, played with an appealing mix of regal bearing and girlish charm by Naomi Cronk.

RMTC/Mirvish The Audience cast

The RMTC/Mirvish co-production features tastefully elegant sets and costumes by designer Christina Poddubiuk. (Dylan Hewlett)

And in the central role — and linchpin of any production of The Audience — Reid is the kind of dutifully solid anchor Elizabeth would probably be proud of.

She's given a daunting task, playing the guarded monarch over a 63-year span. She's less convincing as a pre-coronation Elizabeth meeting with Churchill, with a pinched and high-pitched vocal affectation that doesn't quite work.

As the more mature Elizabeth, though, she's a picture of composure, while also landing her witty barbs with finesse. Elizabeth is a complex character here, and the actor playing her isn't given any pyrotechnic, showy moments. The role demands a complicated stillness which Reid delivers with grace.

Christopher Newton's direction is likewise understated but smooth, keeping the 130-minute production crisp as it spans the decades. And designer Christina Poddubiuk offers up tastefully elegant sets and costumes befitting a queen.

If not totally enraptured, we are amused, and intrigued, by this Audience.

The Audience runs at the Royal MTC John Hirsch Mainstage until Dec. 17, and at the Royal Alexandra Theatre in Toronto from Jan. 17 to Feb. 26, 2017.