John King was the son of Philip King of Worming Hall, Buckinghamshire. He was educated at Westminster and Oxford, taking holy orders in 1590. Rising to become Bishop of London in 1611, he was quick to make use of his talents as a preacher and public speaker. A mural tablet near his grave in St. Paul's Cathedral remembers him as solid and profound divine, of great gravity and piety and as having 'so excellent a volubity of speech, that Sir Edmund Coke would often say of him that he was the best speaker in the Star-chamber in his time'.