Bertolt Brecht was also one of the preeminent playwrights of the 20th-century. He was also a poet and occasional screenwriter who penned a few screenplays. One of his most famous musical plays, Three Penny Opera, was adapted into a film by Pabst in 1931. Brecht worked as a screenwriter in the U.S. during the early '40s and worked with Fritz Lang and John Wexley. He left Hollywood in 1947 so he wouldn't have to testify before the House Un-American Activities Committee. He lived briefly in Switzerland before settling down permanently in East Germany.