There are people who cannot handle fantasy. There are viewers who think that any mention of the specifically impossible (instead of what fiction is normally filled with, which is the "practically impossible" or the "completely improbable") invalidates a story. I know people who like Game of Thrones who get upset at the dragons and the Red Woman and the White Walkers - which is strange, since the very first scene of the first episode has White Walkers in it - they came first. Those elements are "unrealistic", while all the other made up stuff is taken in stride.
For the fantasy deficient, Jonathan Strange & Mr. Norrell must be kryptonite. It is an extremely well-made, well-appointed and attractive pseudo-historical drama about the restoration of English Magic. The central conflict in the story is about two magicians (the only two magicians in the realm) disagreeing on some points of academia. It is a story that, bereft of the magical element could not exist. Nothing would be left. It's also the sort of show that would have been impossible to conceive maybe 15 years ago, and that would have looked flat and cheap (the late '00s Sky Television adaptations of a couple Terry Pratchett novels indicate that - not badly made, but just cheap with seams showing in every single poorly-composited effects shot).
Jonathan Strange & Mr. Norrell, based on Susanna Clarke's 800-page novel, looks sumptuous, with fantastic attention to detail in all of its many sets and costumes and characters. Set in the early 19th century at the height of the Napoleonic wars, it is an adaptation of one of the few great fantasy novels of the current century, which Neil Gaiman has called "the finest English novel of the fantastic written in the last 70 years". Emphasis on the English, for this is very much a series about English character and an English way of doing things - the Southern, London, proper, and modern way, and the Northern mysterious, dark, primitive way.
Mr. Norrell, who lives in the North in Yorkshire but has very much the manners and temperament (if not the social graces) of Modern England, is the pre-eminent scholar of magic in the realm, at a time where gentlemen might study magic, but no gentleman would actually perform it. That is, until Mr. Norrell feels compelled to prove his abilities. After an elaborate demonstration of his skills, and the first performance of magic on English soil in 300 years, he travels to London to avail the country of his skills at this time of war.
Above all, Mr. Norrell wants to modernize magic, which means eliminate all traces of the old kind of magic that abandoned England for so long - the magic of fortune tellers, street performers, and everyone else who pledges allegiance to the legendary Raven King. It is the magic of intuition and passion and, ultimately, madness, and Mr. Norrell wants to expunge it all.
It is also very powerful magic, and the kind that Jonathan Strange, a gadabout with an estate and a girl who won't marry a man without a profession, finds he's very good at. He comes to England to become Mr. Norrell's first pupil. Eventually, they become rivals and even enemies in conflict for the soul of English magic and maybe the country itself.
This conflict is the heart of the story, and these wizards and their very different personalities are central to the success of the series. Mr. Norrell is played by Eddie Marsan as a retiring, fussy, and somewhat sour man who desires recognition but despises attention. Strange, played by Bertie Carvel as a man of manic energy without much focus, is Norell's exact opposite in personality and physicality - being lank and upright where Eddie Marsan seems to be seated even when standing.
What's magnetic about their connection is how Norrell, even at his most despicable (and he does many a terrible thing in the series all in the name of preserving the reputation of English magic) is completely disarmed by meeting another real magician. While his hangers on and adjuncts are advising him to dismiss, discredit, or destroy Strange, Norrell just wants to be friends - completely on his own terms, of course.
The way the series is structured, it’s pretty clear the show wants the audience to side with Strange (it's been a decade since I've read it, but I remember more ambiguity in the book). However, that does not mean they've stacked the deck entirely in Strange's favor, and in fact it is not Norrell's strict, stringent, even discriminatory principles that gets him, and ultimately all of England, into trouble. It is when he breaches these principles.
That is when he gets involved with The Gentleman, a fairy who provides the impetus for much of the personal conflict in the story. The Gentleman is not a fairy in the storybook small naked chick with butterfly wings way, but an old fairy, tall and frightening, who runs a kind of purgatory called Lost Hope where he brings people to dance with him eternally. He enlists the aid of Stephen, a black butler who the Gentleman takes a fancy to. He decides that since he likes Stephen so much, he should become the next king of England, and proceeds to hatch murder plots against the current mad king George III (understanding rules of succession, and other human foibles, is not the Gentleman's strong suit.)
All at once, Jonathan Strange & Mr. Norrell is a story about academic friendship and rivalry, an alternative history of the Napoleonic wars, and a ghost story, all hinged around the two different, particular types of arrogance each of the title characters exhibits. Norrell has a paternal arrogance, where he knows what's best for everybody and will be in control and make everyone do what's right. Strange's arrogance is impetuous and youthful: he can do whatever he wants and the consequences be damned. All of this is wrapped in a very respectable BBC adaptation of a beloved literary property.
It is a relatively faithful adaptation, but that means it is a story taken better as a whole. Each episode fills in pieces of the larger narrative and things that are important in the first episode don't come up again until six hours later, and if you haven't paid attention, you might be lost.
Jonathan Strange & Mr. Norrell is a fantasy nerd's dream. For a complete fantasy nerd like me who loved the book (despite some infuriating aspects, like an inability to properly end) this series is a marvelous companion. It is so handsomely made and the central performances are so well conceived and executed that some narrative issues, a few less than engaging episodes and some places where the show just felt long did not bother me. They might bother a more general audience, who could find the whole thing a bit silly. For me, it was exactly what I wanted out of an adaptation.
The Blu-ray of Jonathan Strange & Mr. Norrell contains a single bonus feature, a making of featurette, which is pleasant as these things go, lots of talking heads about how much they loved working on it, and while it shows very little actual behind the scenes action there are some shots of the practically built sets that show how far they stretched what I understand was actually a fairly modest budget into making a rare television visual experience.