Richard Brinsley Sheridan became master of both the theatrical and political stages, Fintan O'Toole shows in the first biography of the playwright since 1825. There were enormous contradictions in his character - an accomplished playwright who secretly hated the theatre, a Whig who had the ear of the heir to the throne, a convinced Irish nationlist who never set foot in Ireland from childhood on. These three extracts sketch in his background, his moment of greatest triumph in the theatre and the development of his political liaison with the Prince of Wales

"While most English bishops in colonised Ireland looked to their native flocks for the spoils of conquest, Bedell genuinely believed himself their humble servant"

The Sheridan family was Protestant, and the product of a unique experiment in Bible-based Gaelic Protestantism which took place among the drumlins of Cavan. In his biography O'Toole traces the effect of that legacy on Richard Brinsley Sheridan: an obsession with words and their meaning.

The 19th-century historian, W.E.H. Lecky, writing his great treatise on the 18th century, felt it necessary to begin with the insurrection of 1641. And he did so with good reason, for in the words of Roy Foster: "What people thought happened in that bloody autumn conditioned events and attitudes in Ireland for generations to come". Lucid and exaggerated reports of events that were in any case horrifying enough in themselves were driven into Protestant consciousness, where they remained as a warning against Catholic treachery and an encouragement to hardfaced repression, most immediately in Oliver Cromwell's ferocious campaign against Irish resistance in 1649 and 1650. In 1662, the Irish parliament declared that the first day of the rebellion should be "kept and celebrated as an anniversary holy day in this kingdom forever". John Wesley was chilled to the bone by the blood-curdling accounts of the rising circulating in the middle of the 18th century. Sir John Temple's carefully selective book on the massacres, written in 1646, was still being published in a new edition just six years before the death of Richard Brinsley Sheridan in 1816. Even then, it continued to provide one of the main arguments for the maintenance of repressive laws against Catholics.

And just as that day in October 1641 changed forever the fate of Ireland, so, more intimately, did it shape the destiny of one branch of the O'Sheridan family in Cavan.

The bishop's house in Kilmore, a remote settlement nestling amidst the woods, bogs and drumlins - "little hills rising n the forms of hogs' backs" - of a pleasant, rolling landscape, was occupied by William Bedell, the son of an Essex yeoman, who had been sent to Ireland as Provost of Trinity College Dublin and then been made Bishop of Kilmore in 1629.

Less than a mile away, at Drumcor, in a small farmhouse by the side of Lough Oughter, lived Donnchadh O Sioradain. O Sioradain was a native and a Gaelic-speaker, but a convert to Protestantism. He seems to have been orphaned at an early age, educated as a Protestant by a local English minister, and married to an Englishwoman called Foster. Bedell took a special liking to him and valued him for his "good conversation and skill in the Irish language". The Bishop made O Sioradain a minister, and granted him a living in the parish of Killesher. But O Sioradain was still very much an Irishman, close to his people and his family, who were, after the O'Reillys, the "most numerous and potent" in Cavan.

That O Sioradain's skill in the Irish language was valued by Bedell is not as surprising as it might seem, for Bedell himself was a virtually unique figure, an English Protestant divine who believed it his business to bring light to the native Irish, to come as a missionary rather than a conquerer. While most English bishops in colonised Ireland looked to their native flocks for the spoils of conquest, Bedell genuinely believed himself their humble servant. Granted two dioceses, Kilmore and Ardagh, he gave up the latter, hoping to set an example of humility to his fellow bishops. Explaining his action, he wrote to his friend Samuel Ward in Cambridge that it was the fault of the Protestants that the native Irish preferred to stay loyal to their Catholic priests: "The Popish clergy is double to us in number, and having the advantage of the (Irish) toung, of the love of the people, of our extortions upon them, of the very inborne hatred of subdued people to their conquerors, they hold them still in blindness and superstition, our selves being the cheefest impediments to the worke that we pretend to set forward."

Bedell set in train one of the most poignant enterprises in Irish cultural history, the translation of the Old Testament into Irish. He learned the language himself "taking to his assistance one Mr King and Mr Dennis Sheridan, both Irishmen and clergymen and excellently skilled in the language of their own country, whose office it was to translate the English version into Irish". Every day, at one o'clock in the church in Kilmore, Bedell had his deacon, Owen O'Sheridan, another of the O'Sheridan converts, read in Irish from the Book of Common Prayer "for the benefit of those he had brought from popery but understood not the English tongue".

Bedell's translations were not just instruments of conversion, but also placed in the hands of the Irish poor for the first time ever, comprehensible texts of the Scriptures, which were in fact used in Catholic Masses as late as the 1970s. He also engaged the local Catholic priests and scholars in theological argument, treating them with respect and "the learnedest of them" was "my loving brother Cohonaght O'Sheridan", to whom he wrote in Latin with "the desired effect". At least three of the Sheridans around Kilmore - Donnchadh, Owen and Cohonaght - therefore became Protestant clergymen.Through Bedell, the O'Sheridans had become involved in one of the bravest, oddest and most potentially far-reaching enterprises in Irish history: the attempt to found, in the drumlins of Cavan, a Gaelic protestantism, to escape the identification of Catholic and Irish, Protestant and British, that would bedevil that history for centuries. It was a noble project but a doomed one. Bedell was under constant suspicion from his own religious and political superiors, who looked with suspicion on his respectful attitude to the Irish Catholics. And ... the Irish catholics put an end to his mission by rising up in rebellion that would shape for centuries the sectarian contours of Irish history.The rebellion reflected the complex nature of religious and political power in Ireland at the time. The Protestant reformation had made little progress in Ireland: a vast majority of both Gaelic Irish and of the descendants of early settlers (the so-called old English) were still Catholic. But the newer English and Scottish settlers were Protestant, and their increasing power placed new strains on the loyalty of the old English. So long as Charles I, with his policy of relative religious tolerance, remained in control in England, those strains could be contained. But when, from 1640 onwards, his power was threatened by the militantly Protestant parliament, the old English and Gaelic Irish began to look to their mutual interests as Catholics. Charles I, realising that they could be of considerable use in his struggle with parliament, encouraged the arming of the Gaelic Irish in Ulster. When they rose against the Protestant settlers in October 1641, therefore they did so in the name of the king. After a few weeks, the old English Catholics joined them, and a clear identification between religion and politics began to take shape in Ireland. In what gradually became a civil war between Catholics and Protestants, William Bedell's attempts to blur the distinctions between Gaelic and Protestant were doomed to failure. Instead, he and his allies among the Sheridans became foot-notes in a long saga of atrocity and counter-atrocity as war set up a 10-year reign in Ireland.Beginning on October 23rd, 1641, the Irish chieftains of Ulster launched concerted attacks on the English and Scottish settlers, killing perhaps 2,000 of them. In Cavan, Edward O'Reilly was more moderate, sacking some houses but for the most part merely urging the settlers to leave. After a fortnight, crowds of refugees, most of them destitute and half-naked, began to arrive at Bedell's house in Kilmore, where they were given shelter. Bedell was unmolested, the rebels telling him "you should be the last Englishman that should be put out of Ireland". So well trusted was Bedell, indeed, that the rebels asked him to draw up a statement of their grievances for delivery to the Lords Justices of Ireland. It was a markedly more minimal set of demands than those set out in statements in other parts of the country, playing down religious issues and concentrating on threat to land titles, the depredations of the government and, significantly, a residual royalty to the king . . .When eventually the rebels decided to evict Bedell from the bishop's house and install his Catholic rival, the bishop was imprisoned in the dismal Cloughoughter castle, built on a rock in the lake, over Christmas. (Donnchadh) O'Sheridan, however, helped persuade Edmund O'Reilly to release him. Bedell chose to move with his family to O'Sheridan's house nearby, which was already a sanctuary "to as many distress'd English as it could contain".When Sheridan's comic masterpiece, A School For Scandal opened in 1777, its exposure of hypocrisy, in an era when the old caste-system was falling apart, was literally calamitous, and earned the writer a huge reputation."FREDERIC Reynolds, 12 years old, thought he was going to die. He was walking down the narrow passage between Vinegar Yard and Bridges Street at nine o'clock on a May evening in 1777, when he heard a terrible noise above his head. The sudden, tremendous rumble made him sure that Drury Lane Theatre, which formed one side of the passage, was collapsing, and that he was going to be killed. He covered his head with his hands and ran for his life, but found the next morning that the noise did not arise from the falling of the house, but from the falling of the screen in the fourth act; so violent and so tumultuous were the applause and laughter." He had passed by the opening night of Sheridan's new play The School For Scandal.Well into the 19th century, seeing the play in its early days was something to boast of, as if it had a meaning then which could never quite be recaptured. Great critics were apt to go mistyeyed at the memory. William Hazlitt, reviewing a production in 1815, asked "Why can we not always be young, and seeing The School For Scandal? ... What would we not give to see it once more, as it was then acted, and with the same feelings with which we saw it then?" Charles Lamb in 1822 wrote that: "Amidst the mortifying circumstances attendant upon growing old, it is something to have seen The School For Scandal in its glory." What they longed for was not simply to see the play - for it was still being revived continually - but to have seen it then, at that moment between the American Revolution and the French when a new world seemed to be in the making and that play somehow a part of it.What had caused the noise of delight mingled with terror that Frederic Reynolds heard? On stage a screen had been dashed down and there, cowering behind it, was the scandal-monger Lady Teazle, her duplicitous relationship with the hypocrite, Joseph Surface, exposed to the full view of both her husband and the audience. What Joseph Surface called "my politics" - scheming, double-dealing, injustice - had been stripped naked and exposed to the scrutiny of all under the light of the chandeliers. And the analogy with politics in the broader sense was made unmistakably plain to the audience with barbed references to Benjamin Hopkins, opponent of the radical hero, John Wilkes, in a struggle for the office of chamberlain of the City of London. If in the play the feckless Charles Surface, rather than his apparently upright brother Joseph, could emerge as the triumphant hero, then so too could Wilkes the good-hearted rake be a fit hero for the people.Yet those echoes of contemporary politics hardly explain the explosive impact of such a simple if ingenious piece of stage business as the knocking over of a screen. Why should the exposure of hypocrisy, the revelation of what might lie behind a smooth personal surface, be so tumultuous? Why should a play, with a consistently light touch, in which wit and laughter keep pain and despair at bay, have seemed so morally serious? Why does it matter that the trivial intrigues of an inconsequential cabal are exposed? Because the play's concerns - reputation and reality, appearance and emotion - were vital not just to private behaviour but to political life. The idea of reputation was at the heart of the Enlightenment's attempts to understand what, in the late 18th century, it meant to be modern. In fact it was a specifically modern concern, arising from the emergence of a phenomenon that had not been experienced before, namely urban life on a large scale. Big cities like Paris and London threatened the moral intimacy of the old regime. Previously when people had remained within their allotted circles in life, those who met them could know who and what they were. If you knew what someone was - a peasant, a tradesman, a lawyer, an aristocrat - you knew who they were. And until recently you could have told what someone was by looking at them: their clothes, their movements, their manners, their speech, gave them away. But in the bustling, open life of the city, this was no longer possible. The new city was too diffuse. It was too full of incomers and social climbers.GEORGE III was mad, and his son, the Prince of Wales, who supported the Whig cause, became an extremely important figure politically. Sheridan gradually became the power behind the prince, as he put himself at peril by marrying a Roman Catholic secretly.WHEN Frances Sheridan (Richard Brinsley Sheridan's mother) died in France back in 1766, her husband Thomas, even in his grief, had taken pains to ensure that their children were left in the care of good Protestants. Later, when their son Richard was in France with Eliza, he was not so particular about religion, getting a Catholic priest to marry him, and allowing his wife to stay in a convent. He was, at least outwardly, an Anglican, but his attitude was close to that of his sister who, in a letter in 1797, put it to him that, "I am in moral and political notions a Protestant as well as in religion, and I admit it to be very possible that a person may be right who neither says nor does as I do". Richard's private beliefs tended towards agnosticism and he later described his attitude to religious faith as one of "selfish incredulity" that was "not quite hardened" into outright atheism.This kind of loose religious affiliation was not that of the British state and, more particularly of its monarchy which essentially embodied the notion of an indissoluble link between Britishness and Protestantism. In the mid-1780s, however, this absolute assumption was fundamentally threatened in a way that it had not been since the Glorious Revolution of 1688. Richard Sheridan found himself close to the epicentre of what could have been a constitutional earthquake. In 1784, the Prince of Wales fell in love with Mrs Maria Fitzherbert, twice widowed and six years older than himself. There was nothing surprising or problematic about a young heir to the throne fawning on a more experienced woman. The problem was that Mrs Fitzherbert not merely came from an old Roman Catholic family in the north of England, but that she was awkwardly serious about her religion. For the Prince of Wales to keep a Catholic mistress would be a scandal well within the broad latitude allowed to royalty. But a good Catholic like Maria Fitzherbert would never consent to be a mistress. And for the heir to the throne to marry her would be not scandalous, not even intolerable, but illegal to the point of treason. Two keystones of the constitution - the Act of Settlement and the Royal Marriage Act - absolutely forbade it. At best, the prince would have to give up the throne. At worst, the legitimacy of the Protestant monarchy could be called into question.For Sheridan, this most awkward of entanglements had the effect of tightening his own hold over the prince. Previously, the prince had looked to Sheridan for friendship, but to Fox [the leader of the Whig party] for political guidance. Fox, however, made no secret of his fierce opposition to any marriage with Mrs Fitzherbert, and the prince for his part decided to lie to his mentor, assuring him that "there not only is but never was any ground" for rumours that he would marry her. Mrs Fitzherbert, for her part, knew that Fox wanted her to be content with the role of mistress and hated him for it. The combined effect of his own breach of trust and of his beloved's influence was to weaken the bond between the prince and Fox, and to make Sheridan, a 35-year-old Irish actor's son, the most trusted adviser to the heir to the British throne. It was a moment that would shape the rest of his life, conjuring up a tantalising vision of great power that would remain always in sight and always out of reach.Events came to a head on December 15th, 1785 when, in the drawing room of Mrs Fitzherbert's house, she and the Prince of Wales were married by a young, debt-ridden Anglican priest. The only others present were the bride's brother and uncle, but the Prince wrote out a marriage certificate which he, his new wife, and the two witnesses signed. Almost at once, London was humming with rumours, not only that the Prince had married a Catholic, but that the ceremony had been performed by a Catholic priest. Soon the rumours were given both physical form and direct political content. In March 1786, the great political cartoonist James Gillray published a print in which the Prince and Mrs Fitzherbert are being married in a French Catholic church. The priest is Edmund Burke, already established in cartoon iconography as an Irish Jesuit. The bride is being given away by Fox. The two witnesses are the Prince's crony, George Hanger, a notorious rake and dandy, and Sheridan, who stands with a napkin under his arm and a bottle of wine in each of his coat pockets, presumably ready to serve the wedding feast. The print sold in very large numbers.SHERIDAN'S wife Eliza, tired of his neglect, fell in love and had an affair with the young Irish revolutionary, Lord Edward Fitzgerald. She became pregnant by Fitzgerald, which speeded her death from tuberculosis. Sheridan agreed with Fitzgerald, however, that he would rear the child, and so his personal as well as his political life began to run parallel to Fitzgerald's. Shortly afterwards hey even proposed to the same woman.LATE in 1791 Sheridan had met, and become fascinated by, two of the more interesting of the French exiles who were gathering in England. Madame StephanieFelicitie de Genlis was a devotee of Rousseau and a celebrated educational theorist and sentimental novelist. She was also the mistress of the Duc D'Orleans, the cousin of Louis XVI who had adopted revolutionary ideas and styled himself Philippe Egalite. She had with her 19-year-old Pamela, widely assumed to be her daughter by Egalite. For Sheridan, Pamela had a special attraction: she was strikingly like a younger Eliza. She had the same pale skin and high forehead, the same dark eyes and deep brown hair.Because of their revolutionary associations, Pamela and her mother ... were shunned by respectable society. Horace Walpole referred to Madame de Genlis and Talleyrand as "Eve and the serpent", and trusted that "few would be disposed to taste their rotten apples". But Sheridan, for both political and personal reasons, was disposed to bite. [After Eliza's death, de Genlis and Pamela set off for Dover, destination France] ... but found with a rising sense of alarm that they were being taken by odd roads and that, after a long time, they were nowhere near Dover. They panicked and ordered a coach back to London where they drove to Sheridan's house. There the post-boys confessed that "an unknown gentleman" had persuaded them to drive around in such a confusing meander. Sheridan then volunteered to take them to Dover himself but added that it would be a few days before he was free to do so. He then took them to Isleworth where they remained as his guests for a month. The suspicion that the whole thing had been arranged by Sheridan is strengthened by Madame de Genlis's claim in her memoirs that he had, two days previously, declared his love for Pamela. He had asked for, and been promised, her hand in marriage. All of this happened at around the same time as Mary's death, [Fitzgerald's daughter by Eliza] and it seems that Sheridan had dreams of finding, in Pamela, a substitute for the dead Eliza. He may even have arranged to follow her and Madame de Genlis to France. While they were travelling, however, they were overtaken on the road by a man who now styled himself "le citoyen Edouard Fitzgerald". He too had left England for Paris, where he began to discuss the idea of an Irish revolution with another radical exile from Ireland, Henry Sheares. While there, he had seen Madame de Genlis and her ward at the opera, and had been, like Sheridan, thunderstruck by Pamela's resemblance to Eliza. Like Sheridan, too, he waylaid their journey, and proposed to Pamela. She may have assumed that [Sheridan] had lost interest ... She accepted Fitzgerald's proposals and they were married at Tournai. The witnesses, who could testify not just to a wedding but also to the extraordinary intermingling of revolution and royalty, included both Philippe Egalite, soon to die on the guillotine, and the future king of France, Louis Philippe. Shortly afterwards Fitzgerald and Pamela settled in Dublin and gradually wove themselves into the emerging Irish revolution.These extracts are from A Traitor's Kiss by Fintan O'Toole, which will be published by Granta on October 30th, price £20