Charles Marowitz: Iconoclastic director who founded the Open Space Theatre and kick-started the careers of many fine actors and writers

Armed with radical techniques gleaned from the New York Actors Studio and an unquenchable desire to upset the apple cart, Charles Marowitz was an adrenaline shot into British theatre. He was a key player in the evolution of the Fringe, and his work as a director, playwright, critic, teacher and as mastermind of the Open Space Theatre kick-started the careers of a long parade of exciting actors and writers. And even if most traces of those dog days of the 1960s and '70s, when lunchtime, late-night and touring plays could all be seen in shoeboxes above or below pubs have long since blown away, his influence lives on.

Speaking on the BBC's Arena in 1975, playwright Trevor Griffiths described the Fringe at its best as offering "collaboration instead of manipulation… actors who weren't theatrical, directors who weren't afraid of ideas and theory, and audiences for whom theatre-going was part of a general commitment to change rather than to anodyne social convention." The Fringe was theatre to its square root, its creators a militia who by the mid-1970s, Kenneth Tynan observed, were no longer a tributary but a separate river raging alongside the mainstream. Its decline in the '80s, no longer able to survive on Arts Council diets of "peanuts and promises", was horribly apposite.

Born in New York in 1932, Charles Marowitz grew up on the poverty-stricken Lower East Side to Polish Jewish parents who worked in the clothing industry and spoke not a word of English. School did nothing for a born non-conformist like him, except to introduce him to drama. He quickly acted on the discovery, staging a production of Dr Faustus at the Labor Temple when he was 14, forming his own acting company and writing stroppy reviews for Village Voice.

After serving in Korea he enrolled at the London Academy of Music and Dramatic Art, but "having proved myself a failure at drama schools both in New York and London, it seemed the most natural thing in the world to set up an acting school of my own, if not to edify others then at least to instruct myself." As well as co-founding the theatre journal Encore, he formed a company called In-Stage in 1958, freeing actors to improvise around established and often sacred texts, and he also directed work by Saul Bellow at an early incarnation of the Traverse in Edinburgh before assisting Peter Brook on a production of King Lear.

The partnership was alchemical. Marowitz, with the experiences of group experiment he'd brought with him from America, and Brook, with a sound grasp of theatrical conventions and a desire to smash them, together presented the RSC's Theatre of Cruelty season, which spawned such scarring events as Brook's production of Marat/Sade at the Aldwych, which, with its confrontational, naked intensity, inspired and helped to kick-start what would become the Fringe.

As well as running workshops, he directed, among other things, the first successful production of Joe Orton's Loot at the Jeanette Cochrane Theatre. Then in 1968, he got wealthy patrons including Harold Pinter and Michael Winner (two names one doesn't often see side by side) to cough up and allow him to begin the Open Space in a disused old people's home on Tottenham Court Road. He was aided by Thelma Holt as executive director, who, in their intense though platonic 12-year partnership, acted her socks off, cajoled and bullied money out of sponsors, stuffed vitamin pills into malnourished performers' mouths and stuck egg boxes across the ceiling for soundproofing. Marowitz never underestimated her importance: "We survive to a large extent because Thelma Holt is a witch and a miracle maker."

As well as works by Strindberg, Beckett and Howard Barker, Open Space staged Marowitz's iconoclastic interpretations of the classics: in a kaleidoscopic Hamlet, his dislike of the privileged, petulant noble and his blunt assertion that Shakespeare could be guilty of "some horrifically bad writing" resulted in him having the Prince rape Ophelia.

In 1976 EMI began redeveloping the block the Open Space occupied. They promised a home within the new complex: Marowitz relocated to temporary premises in a disused post office in Euston Road. EMI never honoured their promise. Then came the "Pink Bathroom" scandal the following year, when Marowitz was accused by the salivating right-wing press of using production funds to buy himself a new bathroom suite. He insisted it was for a set, but the affair badly dented his integrity. Holt parted company with him the same year, and the Open Space closed two years later.

He returned to America and recreated the Open Space in Los Angeles, then ran the Malibu Stage Company, while writing copious books on dramatic theory and history. One of his Open Space works (which he referred to and collected under the self-deprecating title of "Potboilers") made it to Broadway in 1987. Typically, Sherlock's Last Case showed no reverence for the esteemed original stories.

His spirit of defiance was never tempered: to the end he was making people angry, especially those he worked with. But it was part of a furious and devoted personality that produced some truly mighty theatrical innovations which exemplify and deify the era that was his heyday. As the playwright Wilson John Haire commented on learning of his death: "it must truly be the end of the Sixties."

SIMON FARQUHAR

Charles Marowitz, playwright, director and critic: born New York 26 January 1932; first marriage dissolved, 1982 Jane Allsop (one son); died Agoura Hills, California 2 May 2014.