FOR those who don’t remember the Cold War at its height, it’s probably difficult to imagine the shock and impact the Cambridge Five had on Britain.

However, the two-part documentary Kim Philby – His Most Intimate Betrayal should go some way to redressing that.

It focuses on arguably the most famous of the quintet, Harold Adrian Russell Philby, nicknamed Kim after the famous Rudyard Kipling character.

Born in India in 1912, he was the son of author and orientalist St John Philby, and was educated at top British establishments before becoming interested in politics.

It was during the Second World War, while working for the Special Operations Executive, that Philby became of particular interest to the Russians and, for years afterwards, he passed secrets to the KGB.

Writer Ben Macintyre argues that the key to Philby’s success was his friendship with Nicholas Elliott, a colleague at MI6 who unwittingly supplied him with information and who defended