Firstly, a confession: I've never watched the TV series Downton Abbey. But - much to my pleasant surprise - I had a good time anyway.
How much a movie based on a TV series should be self-contained is arguable: here, though one of the uninitiated, I could still enjoy the story and characters. Those who have assiduously followed the series will no doubt get even more out of it since a lot of backstories are obviously involved that will be most appreciated by the devotees.
If there's a criticism to be made regarding this, it's that the film is stuffed with so many characters and their storylines: even with the odd actor not returning, these would no doubt have unfolded with much more detail in a series. They sometimes seem a little rushed in a two-hour film.
Certainly Downton Abbey looks beautiful on the big screen - the costumes, settings and countryside are ravishing.
Of course, there's no shortage of movies and TV shows dealing with this sort of upstairs/downstairs British world of rich folk and their staff - The Remains of the Day and Gosford Park, to name two - so the general milieu is familiar enough.
And on the subject of Gosford Park, the main creative force behind Downton Abbey both on television and here is Julian Fellowes, who won an Oscar for writing the former. Michael Engler, who directed episodes of the TV series, is also back, but there's no doubt it's Fellowes' show.
It's 1927. The Crawley family - headed by Robert (Hugh Bonneville) seventh Earl of Grantham, Viscount Downton who is married to the American Cora (Elizabeth McGovern), Countess of Grantham, Viscountess - are reflective. They wonder if their world and their privileged way of life - big house, lots of servants - is going to last. But even the Crawleys have their betters and they have a much more pressing matter with which to deal.
A letter arrives that King George V (Simon Jones) and Queen Mary (Geraldine James) will be visiting Downton Abbey - there will be a dinner and a parade - and both the Crawleys and their staff are filled with a mixture of trepidation and excitement.
Lady Mary (Michelle Dockery) asks the family's now-retired butler Carson (Jim Carter) to return to duty for the occasion (apparently in the series he withdrew from the job because of palsy but that matter is not addressed here: perhaps a royal visit has magical healing powers just as the king's touch was thought in the Middle Ages to heal scrofula?). Not unnaturally, this doesn't sit well with Carson's replacement, Thomas Barrow (Rob James-Collier), but they don't have long to quarrel (and besides, Thomas has another, more personal, problem with which he is struggling).
The royal butler (David Haig) - or Page of the Backstairs, as he sniffily informs everyone is his correct title, arrives as an emissary. He announces that Palace staff will take over from the Downton downstairs staff for the duration of the king and queen's visit.
Of course, everyone is outraged. The royal chef - French and temperamental, naturellement - takes over the kitchen and the condescending royal staff act like they own the place. Carson sternly says there will be no tomfoolery but it's not long before the Downton staff plan revenge.
The highlight of the film, not unexpectedly, is Dame Maggie Smith as Violet Crawley, the Dowager Countess. Nobody does haughty imperiousness better than Dame Maggie. Fellowes gives Smith the best lines and she knows what do with them but it's not all withering stares and sharp put-downs: there's a scene towards the end where she reveals a vulnerability that's quite touching.
Violet gets involves in the matter of the will of Lady Maude Bagshaw (Imelda Staunton), Robert's cousin and closest blood relation, who does not intend to leave him her estate.
Along the way the members of the household (both upstairs and down) go through various scandals, revelations, couplings and other intrigues and incidents.
This film will be essential for Downton devotees and others who like this sort of thing mightn't have a bad time either.