Well, darn my drawers and pluck my partridge, if I ’aint just seen a fine gent in an Ascot stroll across my television screen. Unless I’m mistaken, that means ’tis the time of year when us that knows our places, get to have a peek upstairs at ’ow the other half lives.

A gaggle of our thespiest thesps have hit the dressing up box and decked themselves out in a reassuring variety of facial fluffery, starched petticoats and extravagant hats to officially usher in the season of the period drama.

But this isn’t just any period drama (said in the melted-chocolate voice of that woman who does the M&S ads), this is Downton Abbey (Sunday, ITV1, 9pm), a freshly-penned, hand-reared, seven-episode drama from Dorset-based king of the corset caper, Julian Fellowes.

Kicking off with this week’s lavish, scene-setting, feature-length episode, where it’s 1912, the country’s on the brink of sweeping changes and the unsinkable Titanic has just sunk, and with a whopping six further luscious weeks’ worth of period perfection to come, this is a no-expenses-spared bit of televisual gold that even the most jaded viewer should make the most of.

In a nutshell, Downton’s owner, the Earl of Grantham’s son and brother, also his immediate heirs, have sunk with the Titanic, which means a third existing heir, unknown, and worse rumoured to have a job of all things, is now the rightful benefactor of all their lovely lolly.

Family debates, feuds and skulduggery ensue, all alongside a neat little sub-plot based on the arrival of the brooding and secretive Mister Bates – no don’t – who hobbles about with the aid of a stick and yet is employed as a servant by the Earl, clearly not for his skills at legging it up 20 sweeping staircases blancing a whatnot full of sherry schooners but because he was his Lordship’s batman in the Boer War.

Discuss.

Well, the entire household did nothing but.

In an age when your average bustle-fest comes with a budget more restricted than the leading lady’s corset, lavish projects such as this are as rare as hen’s teeth and, while it is a huge walking, talking stereotype, it’s one of the best things you’ll see all year.

Okay, it’s so bulging with drawn-by-numbers characters that if we don’t see a Victoria Wood spoof this Christmas I shall eat my feathered Derby.

We have the classic Upstairs Downstairs, Mrs Bridges/ Ruby combo in the guise of a puce-faced, mob-capped head cook, as plump as the freshly-annihilated ptarmigan she pummels and Daisy, a hapless scullery scamp who just darsen’t say owt about owt on account of her being from below stairs an’ all that.

Then there’s the textbook, Remains Of The Day-esque housekeeper/butler scenario, both seething with unfulfilled desires they keep firmly buttoned under their heaving doublets.

Upstairs it’s also business as usual with Downton’s stiff-upper-lipped, selectively benevolent head of household, Robert, Earl of Grantham (Hugh Boneville), and his beautifully attired American heiress missus, Countess Cora (Elizabeth McGovern), who to Robert’s mama, the demon dowager Countess Violet, played to dizzying levels of parody by Dame Maggie Smith, all bulging boiled-egg eyes and widow’s weeds draped on a skeletal frame, will always be ‘trade’.

Their three daughters range from comely to gorgeous, so that’s all boxes nicely ticked.

The scenery is pure Sunday night viewing porn, with endlessly gorgeous landscapes, honey-hued villages and, of course, the stately pile itself (played magnificently by Highclere Castle), a vainglorious des-res with intoxicating interiors as sumptuously excessive as the Edwardian era itself.

But that’s where the predictability ends and DA’s real strength lies in the fact that it is not the usual adaptation of a classic that we’re all so familiar with and, more to the point, already know the outcome of from the outset.

Here, we can look forward to weeks of delicious twists and turns, and, I predict that before you can say “Mind that step” poor, crippled Bates, so callously seen off the premises in week one will return to give them some stick.