Who created documentary theatre?

Documentary theatre is often attributed to British playwright Peter Weiss, particularly for his work "The Investigation" (1965), which dramatizes the Frankfurt Auschwitz Trials. However, the genre has roots in various movements and has been influenced by numerous artists, including the likes of Bertolt Brecht, who emphasized the use of real-life events and social issues in theatre. Over time, many playwrights and companies have contributed to its development, making it a collaborative and evolving form of performance art.