It wasn’t that long ago when those seeking costume dramas were limited to “Masterpiece Theatre” and scuffles over Grandma’s wardrobe at an estate sale. Cable changed all that. Showtime’s “The Tudors” and History Channel’s “Vikings” are two examples, both slathered with extreme violence and gratuitous flashes of flesh.

For those who like their dress-up parties with a more modest theme, the offerings remain slim.

A noted breath of chaste air floats in on “Julian Fellowes Presents Doctor Throne,” a four-part miniseries now streaming on Amazon Prime.

Certified Anglophiles will recognize the name of the “presenter” as the creator of “Downton Abbey.” In addition to writing all four parts of his three-hour film, Fellowes serves as host and debriefing agent, enthusiastically waxing on about his take on one of literature’s near-classics.

Fellowes has good reason to gloat. This adaptation of Anthony Trollope’s novel, part of the series known as the “Chronicles of Bersetshire,” gives its interpreter opportunity to wield his most powerful weapon: the royal dis.

The players, aristocrats jockeying for position in 19th-century England, have plenty of reason to drop asides that sound like innocent bon mots, but are really time-detonated bombs that go off shortly after the victims have departed the parlor.

The fuss is over the courtship of Mary (Stefanie Martini), a catch and a half if it weren’t for her “commoner” social status and rumors she was sired out of wedlock.

“If you wish to see me happy again, marry money!” insists one suitor’s mother, Lady Arabella Gresham, played to the hilt by “Inspector Lewis” veteran Rebecca Front.

Mary’s chief defender is the title character, embodied by Tom Hollander, an inventive actor who brings a warm heart, a mischievous side grin and nervous energy to an otherwise thankless role.

Trollope, who despite churning out more than 40 novels has been overshadowed by contemporaries Charles Dickens and William Thackeray, specialized in happy endings, and Fellowes does little to veer off the path. Even contemptible characters come across as misunderstood bullies, most notably Ian McShane’s Roger Scatcherd, a railway magnate who loves whiskey much more than choo-choos.

The role of the Ugly American is played with such radiance by “Community” graduate Alison Brie that you’ll pray she lives long enough to spend her golden years killing “Abbey”s Dowager Countess with kindness. Any moments to contemplate the deep-seated sexism and social discrimination of the era are consistently interrupted by an off-screen orchestra so imposing its members must have been paid by the note.

The optimistic nature of the (very) basic story is matched by the scenery. Director Niall MacCormack got lucky, shooting in the picturesque countryside during a particularly sunny English summer. Buckinghamshire, seen in “Little Dorrit” and “Cranford,” should see a nice uptick in tourism.

Three hours on the sunny side of the street may give jaded viewers heatstroke, but Fellowes gives ample warning in his first introduction. “This is an 1850s story about love, envy and greed,” he says, sitting pretty in front of a crackling fireplace. “Mostly love.”

If Paul McCartney can fill the world with silly love songs, Fellowes should have license to do the same for small-screen romance. Twitter: @nealjustin