During his long career in Hollywood, Mankiewicz wrote forty-eight screenplays. He also produced more than twenty films including The Philadelphia Story which was nominated for the Academy Award for Best Picture in 1941. However, he is best known for the films he directed, twice winning the Academy Award for Best Director. In 1944, he produced The Keys of the Kingdom, which starred Gregory Peck, and featured Mankiewicz's then-wife, Rose Stradner, in a supporting role as a nun.