Some theatres are much more than just buildings and institutions - they have attained the status of cultural myths, places that represent ideas about art and society and that are known to many more people than a small coterie of regular theatregoers. Pre-eminent in this category are London's Royal Court Theatre and Dublin's Abbey Theatre.
Although the Royal Court has a history of provocation that goes back to J.E. Vedrenne and Harley Granville Barker's 1904-7 seasons (which established George Bernard Shaw), it is chiefly known for staging one of the most significant opening nights in postwar theatre history: John Osborne's Look Back in Anger in 1956. With the arrival of the "angry young men", a phrase coined by the Royal Court's press officer, the theatre made an unforgettable contribution to the wider cultural scene.
Since the 1960s, the Royal Court has led at least four new waves of innovative writing for the British stage. Most recently, in the 1990s, the spirit of opposition returned with its much-debated staging of Sarah Kane's Blasted and Mark Ravenhill's Shopping and Fucking , examples of a new "in-yer-face" sensibility.
Dublin's Abbey Theatre, which survived fire in 1951 and subsequent rebuilding, has had an even stronger impact on national culture. Starting life as W. B. Yeats's and Lady Gregory's homeless Irish Literary Theatre in 1899, the Abbey - thanks to Annie Horniman's patronage - opened in a former morgue in 1904. Scandalous episodes included early performances of J. M. Synge's The Playboy of the Western World (1907) and Sean O'Casey's The Plough and the Stars (1926), both of which provoked nationalistic riots.
The new Irish government, in an act of cultural enlightenment that Westminster could not match, gave the Abbey an annual subsidy in 1925, and a small theatre, the Peacock, was set up to perform mainly Irish-language drama. Following the 1951 fire, the organisation was exiled for 15 years to the Queen's Theatre, a larger building that needed longer runs of more populist drama to be viable.
After the Abbey was rebuilt on its old site, the late 1960s saw a renaissance of drama, with some of the best Irish writers being performed there. The Royal Court was also a writers' theatre and pioneered some of the best of European avant-garde drama. Both theatres irritated ideologues of left and right with their choice of plays, which helped to define theatre culture and fed into debates about national identity.
The simple act of carrying a republican flag into a pub in O'Casey's The Plough and the Stars provoked the sister of Kevin Berry, a "young martyr" of the Anglo-Irish war, to protest during a performance. Audiences attacked the author's sceptical and anti-idealistic view of the founding icons of the Irish Free State.
Similarly, an audience member at the 1965 opening of Edward Bond's Saved at the Royal Court remembers that the play, with its baby-stoning scene, provoked "the odd physical punch-up in the foyer", as well as a wave of media outrage and rebuttal, during which liberals and conservatives battled over what should or should not be shown on stage. Theatre censorship was abolished in 1968.
Both books thoroughly cover the history of their subjects. Welch starts with Yeats's aspirations in 1899 and Roberts with two chapters detailing the abortive schemes and the coincidences that preceded the establishment of the English Stage Company and George Devine's first season at the Royal Court in 1956. Both also come right up to 1998-99.
But because Roberts's book tells "the story of the Court as it evolved as an institution", with stress on the role of its artistic directors and how they steered between the rocks of risky innovation and the shoals of commercialism, what is missing is any real feel for what the Court's plays looked like in performance. So while Roberts gives clear accounts of artistic policy and his retelling of the great set-piece controversies are cliche-free and quote new material, readers must look elsewhere to find good descriptions of the plays.
In contrast, Welch's longer book mixes an account of the Abbey's artistic directors with synopses of the major plays and gives a good idea of the controversies and debates they inspired. But while he succeeds in giving a detailed history of the Abbey's function as a "laboratory for testing the prejudices of the mind, the nature of emotion, the value of the spirit" for the years up to 1966, the latter part of his book declines somewhat into a disjointed account of plays, with little of the institutional history that balanced its earlier pages.
But there is something exciting about Welch's ambition to show how the Abbey has, to quote Hamlet - as he does in his subtitle - shown the "very age and body of the time his form and pressure". If he does not always succeed in showing how artistic form tries to give a shape to those things - personal emotions and public mentalities - that seem least capable of being easily encapsulated, the attempt is surely laudable.
If Roberts is less ambitious than Welch, his book has a better sense of closure as he revisits, in its final pages, the problems of rebuilding the theatre and accepting extra funding from sponsorship, both of which are themes that hark back to George Devine's early years at the Royal Court.
Both authors rely on primary sources, as well as the printed memoirs of participants, with Roberts especially making good use of interviews with the main players in his story. And, despite the frequently impassioned hothouse atmosphere of the Court and the Abbey, both Roberts and Welch remain cool-headed and fair-minded, although they also seem a bit too indulgent to recent artistic directors.
The moderate and unpolemical nature of both books may be their greatest strength - students will find them essential as reference books - and their greatest weakness. The coolness and objectivity of both authors seems out of synch with the fierce partisanship that the two theatres have inspired among fans. Both books are readable, reliable and fascinating, but one misses the fire of polemic.
Readers and researchers will be indebted to the thoroughness, commitment and attention that characterise these studies, which are a powerful reminder of theatre's impact on the cultures of both nations and its role in defining national identity.
Aleks Sierz teaches journalism at Goldsmiths College, University of London.
The Royal Court Theatre and the Modern Stage
Author - Philip Roberts
ISBN - 0 521 47962 2
Publisher - Cambridge University Press
Price - £12.95
Pages - 254