In Henry IV, Part 2, Shakespeare has the monarch, sleep-deprived and schemed against, lament that "Uneasy lies the head that wears a crown". In his eponymous play, his son, Henry V, also marvels at the burdens of office. "What infinite heart's ease/ Must kings neglect, that private men enjoy."
It is to the credit of this record-breaking production, the latest and most-seen in the NT Live* series, that it also conveys the private griefs of being the monarch, while remaining supremely watchable and, very often, very funny.
Written by Peter Morgan, whose script for the film The Queen gave Mirren the defining role of her late career, the play uses the weekly private audiences between Elizabeth II and her prime ministers (12 so far) as a setting in which to ruminate on recent history, affairs of state, palace protocol, constitutional convention and a host of other matters.
It's quite an achievement to maintain audience interest for more than two hours in an extremely formal interaction which is, by its very nature, low on tension and drama.
But, as Morgan himself remarks in an entertaining interval featurette, it is in such formal settings that we reveal ourselves the most: our everyday conversation is carelessly and inattentively undertaken.