John Digby, Earl of Bristol, was for a long time the ambassador of King James I to the court of Spain. His main charge was to negotiate a marriage treaty, first between Prince Henry and a Spanish princess or infanta, then, after the death of Henry, a marriage involving Prince Charles (later King Charles I). When the negotiations failed, shortly before the death of King James, DIgby was set up as the fall guy. This document is his defence, showing that he had the confidence of King James and that he fufilled his trust.