It started, apparently, with "the American première of The Constant Prince, Jerzy Grotowski's production of an obscure 17th-century play, which was performed in an old church in New York's East Village on a prop-free stage in front of about 100 people. In Polish."
This was one of the first productions to follow the guidelines laid down in Towards a Poor Theatre, Grotowski's manifesto for a metaphysical approach to acting.
He advocated a theatre in which non-essentials – props, sets, costumes, even the script – were irrelevant, because all that mattered was the process of acting.Grotowski's ideas had a strong influence on Peter Brook, Lee Strasberg, Théâtre de Complicité and many others.
Presumably he has not been so popular with writers, however.