Only one royal has made it into the title, but "Mary Queen of Scots" is in truth a regal double bill, and it's as a showcase for the two actresses who play dueling monarchs that it is most successful.
The redoubtable Saoirse Ronan, thrice Oscar nominated at age 24, is appropriately regal and commanding as the titular 16th century queen who lost her head.
Margot Robbie, meanwhile, impresses as well in the opposing role of her cousin Elizabeth I, unwilling executioner, sometime geopolitical rival and full-time ruler of England.
The two women never met in real life, but that hasn't stopped the movies from frequently putting them on film, often together. John Ford's "Mary of Scotland" featured Katharine Hepburn, of all people, as Mary, while a 1971 British venture had Vanessa Redgrave as Mary, Glenda Jackson as Elizabeth and a shameless advertising slogan: "They used every passion in their incredible duel ... and every man in their savage games of intrigue!"
Though director Josie Rourke and screenwriter Beau Willimon ("House of Cards") have something loftier and more contemporary in mind with their new "Mary," the truth is they are not always as far from that description as they might imagine.
Working in close collaboration with historian John Guy, whose authoritative 2004 biography presented the Scottish queen in a more serious, realpolitik light than previous works, this "Mary" does effectively draw parallels between the two as rulers constrained by the restrictive sexual politics of the day.
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Though both were monarchs, no small beer, they were queens at a time when women -- no matter what their status -- had limited agency, and the film is good at detailing how each was hemmed in in different ways by the actions, ambitions and prejudices of men.
Both queens also figured in and had to deal with an exceptional amount of political scheming in relation to each other as well as to the rest of their realm. Left to their own devices they might have been allies, but it was not to be.
Speaking of scheming, "Mary" details so many wheels inside of wheels machinations that even in this inevitably stripped down version of history, it can be hard to follow the plots of Scotland's Lord Maitland (Ian Hart, excellent as always), England's devious Sir William Cecil (Guy Pearce) and more.
Perhaps in an inevitable attempt to balance the film's serious politics and feminist point of view, Rourke has gone in a different direction when it comes to style.