Born in Chicago, Wanamaker left the States in the late 1940s because he thought he might be blacklisted due to his leftist convictions (see McCarthyism). He settled in England, where he continued his career on the stage and in pictures.
Wanamaker was instrumental in rebuilding the Globe Theatre in London. Sadly, he died of cancer before it opened in 1997.
His daughter is actress Zoe Wanamaker.