In the 2010s the character was revived for another television series, this time in colour and staring comedian and presenter Mark Williams of The Fast Show and Harry Potter (as Ron Weasley's father) fame. Though he's six foot one, he has the kind of neither-ugly nor handsome bland English face Chesterton wrote about and portrays a kind and gentle man who blends so perfectly into the background he doesn't interfere with the proceedings with his presence. In one of those wide-brimmed, bowl-crowned hats and a long black cassock Catholic priests used to wear, he looks the part to a T.
Take a moment to appreciate the opening sequence, in which a shadow cutout of Williams' jowly face is both an homage to Alfred Hitchcock and a beautiful visual hook leads to various cutout-paper style animations of church windows and so forth, with a gorgeous and simple string score making up the theme, a leitmotif that's repeated throughout the series on various instruments.
Once again, nobody does period porn like the British, and they make 19(somewhere between 30-50)s rural England look insanely quaint. The roof at the five hundred year old Gothic church leaks, his friend Mrs. McCarthy frets about her prize roses and the yearly flower show, and the countryside frames Father Brown on his everpresent bicycle beautifully. Clothes are period correct, they make use of several Historical Trust properties beautifully and since we're talking pre-Vatican II the priests are in cassocks, background nuns have habits, and there's ecclesiastical costume porn all over the shop for those of us who appreciate it.
From what I understand, not having actually read the source material, Chesterton wrote the stories pretty much like Encyclopedia Brown ones, only for a more adult and perceptive audience. Whereas the clues weren't as obvious as Bugs Meany calling someone "Alfred" though introduced to him as "Al" (which points out he's lying when he says he doesn't know who the kid is) - the story was merely a puzzle strung together with set pieces.
So the challenge for anyone making the story into any kind of series is to really flesh it out with relatable, believable characters and have character development and subplots and so forth. So they set it in Kembleford, a made-up place in the Cotswolds and surrounded Brown with his own "Baker St. Irregulars" - Mrs. McCarthy playing the "kindly old lady who helps run the presbytery", Sid, a chauffeur ex-con that Brown is desperately trying to keep on the path to salvation, Lady Felicia, a local socialite whose garden party and socialite ways rub Mrs. McCarthy the wrong way (and vice versa) and of course the colorful local police detective none too happy that he has a track record of 0% solving murders to Father Brown's 100% when he casually shows up and casually explains why the Inspector, with every due respect but yet again, has arrested the wrong person.
The first police foil was a no nonsense kind of copper who recognized that yes, a priest does tend to need to show up when a corpse is found to do his job of performing the last rites and seeing if the family need pastoral care. They then decided to go the exceedingly tired and annoying Boston Blackie route of replacing him with an ever angry and ever high strung detective with a baseline level of contempt ("Hello, padre"), a Northern English accent (so you just know he's an idiot), and the creepiest child molester moustache seen in decades. Seriously, whoever suggested this man grow a moustache needs to be quietly sat down and explained why ideas are often good, but his aren't. But even though you feel for the actor having to do this insanely tired trope, it's still an insanely tired trope.
What made the show so initially great is that Brown, a quiet and gentle man, is everpresent but not much of an influence on the proceedings, an observer and source of exposition but someone who doesn't overpower or otherwise steal the screen from a clue here, a clue there - because even though it's a very quaint cross between historical drama and a British Murder, She Wrote it's still a mystery show that needs to present clues to be true to Chesterton's vision. Having Inspector Shouty Loudmouth constantly arresting wrong person after wrong person and/or threatening Brown is the kind of theatrical chrome that the show didn't want or need. Speaking of Murder, She Wrote - Kembleford suffers from Cabot Cove syndrome - namely a population of about 100 and with a murder a week is literally deadlier than narcotrafficante-run parts of Mexico, per capita.
And of course, given that the characters are now very well rounded people, the show can go ahead and make changes to the stories (naturally, otherwise everyone has known for decades the butler did it) but also find nuances and McGuffin hooks. The "I can't reveal the murderer because of his confession to me because of the seal of the confessional, but I can influence others to find the killer themselves") storyline makes at least one appearance. But Sid has a dalliance with a beautiful girl who turns out to own a brewery (and at the time unbeknownst to him be married), and when he hears of a fire there runs to it to see if she is okay, which makes Father Brown run after him.
Brown's zeal to find the real killer, apart from saving the wrong person from death at the end of a rope, is to get that person to confess all and make everything right in this world before meeting God in the next. He turns his mind to the problem not because he'd rather be a policeman than a priest, but because it is vitally important to him, spiritually, to make things right. As a priest he's a bit off in terms of the party line, exuding compassion and humanity wherever he goes - he doesn't lecture an actor on his homosexuality quoting chapter and verse of Romans and banging on about what would later be written down as humanae vitae. When ordered to put pressure on a local wicca coven he argues for some degree of religious tolerance and when someone else turns out to have a guru he brought with him from India, he makes no attempt to quietly explain that Jesus is the ONE redeemer in this world, you don't get to pardon your sins by just coming back as a cockroach and trying again. Williams manages to make Brown insanely likeable, which is kind of the point, and the ensemble cast are charming. As a result the show steers clear of ideas or character traits that might turn off modern audiences, keeping the "feel" of an old-timey world.
Naturally, it's the kind of light entertainment that's kept going for years, with Williams and company more than happy to see the syndication money.