• The 1980s was a Golden Age of TV costume drama, with 'Brideshead Revisited' and 'The Jewel in the Crown' watched by millions and passing into legend. The fetishistic fidelity of these works (well over 10 hours long, with seemingly every word of the source novels) betrayed an ideological function - the invocation of a past which, even if traumatic and disruptive, was coherent, linked to tradition (national, literary, class etc.), where Oxbridge and the Empire are central even as they are in decline (e.g. 'Jewel' was all about the fall of the Raj, rather than the foundation of the new Indian state). It is a celebration of a certain traditional conservatism, while present-tense conservatism (Thatcherism) was actively dismantling those traditions. The notion of fidelity to text created a hierarchy - the novel and the author are sacred and must be translated as exactly as possible - that seems hostile to change, multiple interpretations, different voices.

    Parallel to this ransacking of high(ish) culture, however, were classic adaptations of what might be called 'light' literature, e.g. 'The Irish R.M.' Whereas fidelity to the source in the above-mentioned cases led to dramatic inertia, these other programmes have dated much better - because there is no fear of misinterpreting a 'great' or 'serious' author, there is a greater freedom with the source, a willingness to restructure it if necessary to provide narrative coherence and - wonders - entertainment. As a result, 'light' literature produces genuinely classic television, one that isn't content to simply replicate the past, but has pertinent things to say about the present.

    Take the largely under-rated 'Mapp and Lucia', for instance. Not only does its heroine, like Thatcher, have red hair, often speak in an affectedly deep voice, and, under the guise of respecting conservative hierarchies, radically shake up a deeply conservative English social structure, eventually becoming mayor; but the plots touch on pertinent issues such as elections, charity and government subsidies, and the notion of what it means to be English, and what constitutes tradition.

    Further, unlike 'Brideshead' or 'Jewel', it foregrounds its status as a costume/period/heritage drama, not just making a mockery of the genre's traditional pleasures - dialogue, costumes etc. - but in containing within itself its own costume/period/heritage reconstructions (the Queen Bess pageant; the historical tableaux) that are both inherently ridiculous and call into question the functions of such recreations, especially in the 1980s. Further, it uses the elitist assumptions of the genre - that is is literary, more cultured and civilised, more mannerly than violent action movies, say - to relate a series of stories where class, art and manners are used as weopons for truly vicious, shocking ends.

    'Mapp and Lucia' never pretends to be a faithful historical reconstruction. It exults in its own artifice, the mannered affectation of the characters matched in the art deco stylising, the artificial decor and the crazy outfits. The effect is of a musical comedy, so exquisitely stylised that it sometimes achieves the pitch of Wilde in 'The Importance of Being Earnest', where the choreography of the characters and their gestures, the artifice of the surroundings, the composition of the image and the delivery of the dialogue create a kind of visual rhythm as music. This is especially apparent in the second series, where greater attention is paid to composition and the effects achievable by music (e.g. the cow-like accompaniment to Mapp's bovine tread).

    The characters are never caricatures - they are real people playing caricatures in a bizarrely surreal vision of what constitutes a conservative English village. Prunella Scales brings a measure of pathos to the gleefully horrid Mapp; Nigel Hawthorne's Georgie is a masterpiece of physical expression, high-pitched voice and demented outfits. But it is Geraldine McEwan's Lucia that is the regal centre of the show, scheming, ridiculous, cruel, egotistical, childish, yet sublimely serene, whose odd wardrobe only underlines her queenliness (in both senses).

    The final episode ('Au Reservoir') is deeply harrowing, where everything seems about to fall apart - proving daring stylisation (including a magnificent opera sequence, while Lucia is beautiful in Ming the Merciless oriental black) reaps richer dividends than the staidly literary. The opening credits - with its diaroma painting and strangely melancholy English waltz - will haunt you forever.