• by Fern Siegel , January 4, 2013

The third season of British period drama "Downton Abbey," a blockbuster hit for PBS, returns Jan. 6. Millions of Americans are happily hooked, eager to learn what’s happening to the Crawley family, landed gentry we originally meet in 1911, just after the Titanic sinks.

Issues of heirs and upper-crust marriages are set against the backdrop of a country in transition. When war comes, it will devastate Europe — and forever alter life at Grantham, the Crawley’s stately home. It will also usher in the modern age. When season three kicks off Sunday, with Shirley MacClaine in tow, it’s 1920.

The U.K. ITV drama, which has been brilliantly parodied by the BBC as Uptown Downstairs, sends up the class system and the affectations peculiar to period dramas. For many viewers, Maggie Smith's dowager countess is one of the high points of the series. Smith, who won an Emmy for her portrayal of the acid-tongued aristocrat, delivers her zingers with a style few Americans could emulate. Which is why versatile Jennifer Saunders of "Absolutely Fabulous" fame is mimicking her.

What is it about the British? They can pen these epic TV dramas — and then spoof them with unabashed glee. Talk about creative dexterity.

Show creator Julian Fellowes is writing a prequel to his hit show, exploring the beginnings of the relationship between key characters Earl (Robert) and Countess (Cora) of Grantham, set for broadcast after the last episode of the original airs. Clearly, brand "Downton" has a long shelf life — and built-in marketing appeal.

Some 17 million viewers tuned in to "Downton Abbey," season two, a 27% gain over 2011. In an example of life imitating art, Ralph Lauren signed on as national corporate sponsor. PBS said the TV sponsorship is Lauren’s first.

The show also won an Emmy for outstanding costumes, while Lauren won accolades for teaching 20^th-century Americans how to look like English aristocrats. Can a Lauren "DA" label, ala Polo, be far behind?

This isn’t the first time a British period drama took America by storm. "Brideshead Revisited" skyrocketed Jeremy Irons’ career. Once the show finished, he headed to Broadway to star in The Real Thing. Similarly, Dan Stevens, who plays "Downton" heartthrob Matthew Crawley, is currently on Broadway in "The Heiress," based on a 19^th-century Henry James novel.

Apparently, TV confirms Broadway status. And big audience numbers seal PBS' ad appeal.

While not every period drama — PBS or cable — is a "Downton Abbey," it is a potent reminder that when the investment is made, viewers and advertisers are drawn to excellence.