Anhalt started writing at the age of nineteen when he reorganized and re-conceptualized George Bernard Shaw's 1932 political comedy "On the Rocks." He audaciously sent his version to the seventy-three-year-old Shaw, who wrote the young man back, advising him to stop fiddling with other people's plays and to write his own. Instead, Anhalt ended up writing numerous screen adaptations of other writers' novels and plays, and his screenplay version of Jean Anouilh's drama "Becket" won him the Academy Award.