The Rivals was Sheridan's first play, and remains - along with The School for Scandal - one of just two plays on which his reputation in today's theatre is founded. It wasn't, however, an immediate hit. The premiere on January 17 1775 was hampered by unlearned lines, too much smut, puny puns and its sheer length - 17 lugubrious scenes.
Then this 23-year-old apprentice writer delivered a master-stoke. He closed the play immediately, rewrote it and only 11 days later presented 14 sprightly scenes in what was spun in a press release as "prunings, trimmings and patchings".
The remount of The Rivals was a success. Just to make sure, Sheridan published a review under a pseudonym, claiming the play would "certainly stand foremost in the list of modern comedies". (Oh, to write your own reviews.)
That the young Sheridan should have been so skilled at such an audacious age is not as surprising as it might seem. His itinerant parents neglected him as a boy growing up in Dublin and in his miserable teenage years as an underachieving boarder at Harrow.
His father, Thomas, was a wildly ambitious actor-manager and an enthusiastic champion of elocution. Sheridan's mother, Frances, was a bestselling novelist and popular playwright, one of Garrick's favourites, the dominant actor of the day. So theatre was in Sheridan's very marrow.
Sheridan revered his parents - so much so that he freely filched from his mother's unfinished play A Journey to Bath for The Rivals. For instance, Frances's play features Mrs Tryfort, a self-styled "Queen of the Dictionary", who "misapplies" words with the same self-confidence Mrs Malaprop displays with her "nice derangement of epitaphs".
Sheridan wrote a knowingly disingenuous preface to the published edition of The Rivals, acknowledging the first-night disaster and blaming the "errors" on "extreme inexperience... which might in part have arisen from my being by no means conversant with plays in general, either in reading or at the theatre".
Yet his dramaturgy is impeccable. He roots the play in the audience's taste for comic character: from Shakespeare (Mistress Quickly and Dogberry are Mrs Malaprop's antecedents) and Jonson (Sir Lucius O'Trigger, Sir Anthony Absolute bearing Jonsonian monikers that define type) via the Restoration.
"My first wish in attempting a play was to avoid every appearance of plagiary," he claimed, plagiary in the 18th century being considered an acceptable literary convention, but inelegantly flaunting it seen as very poor show.
In poking fun at poseurs, pretentious country arrivistes and snobs, Sheridan pushes the manners and stereotypes of the plays and society of the time to extremes. He does this with the self-confidence of youth. He is attacking attitudes to love and money, marriage and responsibilities, the battle of the sexes, and the age-old tensions between the generations.
He may not be an Angry Young Man, but he's sending up the bourgeois state of affairs. He delights in a theatre of artifice in the playground of the 18th century, the Georgian, horseshoe-shaped playhouse.
Sheridan was satirising a new society, although he signed up to it in one chief respect: that anyone could be a gentleman through their own efforts and achievements rather than through birth or marriage. He was very American in this respect - the revolution in that country was just a year away.
The Rivals is set in Bath, a newly invigorated city: new architecture, new fashions, new intellectual curiosity avidly embraced by newcomers. Bath offered a levelling of society. There was no hierarchy to be observed in the ballrooms, for example. But it also bred snobbery from the old order. With a fondness for the new comes the posturing of the nouveau.
Bath was also where Sheridan had spent the most tumultuous time of his life on leaving school, as an employee of his father's elocution academy (there was a ready market in social climbers looking to knock the edge off their common accents).
Fintan O'Toole's 1997 biography of Sheridan, A Traitor's Kiss, carefully unpicks what has hitherto been glossed of this period in his life. O'Toole entertainingly shows how Sheridan's life and romantic entanglements had captured the public's tittle-tattling imagination. It was this that would later feed into The Rivals.
Flirting around the city as a young beau in a holiday-romance atmosphere, Sheridan became increasingly besotted with teenage soprano Elizabeth Linley, daughter of one of his father's musician acquaintances. Plenty of other men in Bath felt the same way. Her reputation was at stake.
She was betrothed to a man three times her age as part of a business deal with her father. The wedding was called off, but with a £3,000 pay-off and diamond necklaces thrown in. This raised a few eyebrows, not least Samuel Foote's, the one-legged actor-manager known as "the English Aristophanes", who wrote a scurrilous play, The Maid of Bath, based on the innuendoes.
Elizabeth had another suitor, a reprobate married man, Thomas Mathews. So dismayed was Elizabeth at his uncouth attempts to seduce her that she fled to France for a convent, with Sheridan as her protector.
Sheridan harboured secret desires for Elizabeth. When she nearly died of a tuberculosis-like malady crossing the English Channel, he declared his passion. To avert controversy - or so they thought - they married in France, which caused further scandal, especially because neither had sought the permission of their fathers, despite both being under 21.
Mathews was also affronted and challenged Sheridan to a duel, which they fought with swords, by candlelight, in a London tavern on the newlyweds' return to England.
It was inconclusive and ill-tempered, and Mathews continued to play out his hostility in the pages of the Bath Chronicle. Sheridan's credentials as a gentleman were called into question and a further, drunken duel followed outside Bath. Mathews savagely attacked Sheridan, slashing his neck and piercing his stomach with the broken hilt of his sword.
Far from demeaning Sheridan, the affair brought him celebrity, which incensed his father, who exiled him from Bath to London to study law. In his own mind, Sheridan was now a romantic hero. By duelling he had also established himself as a gentleman. As such, he could not let his wife's lucrative singing career support their marriage: that would be dishonourable.
It was his duty now to earn a living. So he cashed in on his fame, writing a play in a couple of months that mischievously wove elements of his personal drama - a surfeit of suitors, forbidding fathers, daft duels - into the plot of The Rivals.
Compared to his European contemporaries, like Beaumarchais and Schiller, Sheridan was no radical. His achievement was to take the theatrical conventions and social etiquette of the time, to polish them and make them sparkle on stage.
Revelling in artifice and scintillating language, Sheridan none the less reveals a little of himself on stage. And since human behaviour, snobberies and neuroses have changed little since then, he exposes much of our own vanity.
· Simon Reade is joint artistic director of Bristol Old Vic. The Rivals is at Bristol Old Vic until June 12. Box office: 0117-987 7877
