"You are one of the unremembered heroes of the war," wrote Lord Beaverbrook to Archibald Sinclair in 1961, no man acted with more balance, with more judgement or greater restraint than yourself. Sinclair, a wealthy landowner from the north of Scotland, was Liberal Party leader from 1935 to 1945 and Air Minister throughout Winston Churchill's ministry during the Second World War. He played a crucial role in both the Battle of Britain and in the...