The Ipcress File

Who did Michael Caine play in The Ipcress File (two nouns)

Good question.In film Michael Caine plays Harry Palmer, the protagonist.
However, the novel's protagonist Len Deighton on which the film is based has been nameless.
In Chapter 5 of the book, he remarks, "My name is not Harry, but in this business, it is difficult to remember whether he had ever been."

Harry Palmer