Diary reveals how UK-US intelligence relationship evolved in Second World War

Undated handout photo issued by GCHQ of the private diary of Commander Alastair Denniston, the first Head of the GCHQ, which reveals intelligence meetings that took place with US counterparts during WW2 (GCHQ/PA)
Undated handout photo issued by GCHQ of the private diary of Commander Alastair Denniston, the first Head of the GCHQ, which reveals intelligence meetings that took place with US counterparts during WW2 (GCHQ/PA)