While serving as a wireless operator in the military, he mistakenly led the British Army of the Occupation in Germany into the Russian zone.
Powell made his first Hollywood connection with director Irving Lerner who chose him to design the costumes for The Royal Hunt of the Sun (1969), which required styling both the Spanish conquistadors as well as the Native Americans.
Powell returned to Broadway as set designer for a revival of Noël Coward's Private Lives and Peter Shaffer's Lettice and Lovage, both starring Maggie Smith.
Additionally, Powell created the costumes and sets for the French stage production of Amadeus, in which Polanski starred as well as directed.
Returning to the stage, his lavish and luxuriant costumes for Norma Desmond in Andrew Lloyd Webber's musical Sunset Boulevard (1993 in London; 1994 in the USA), based on the movie, earned him another Tony Award.