End of the Middle Ages. Let's start some modern history'. God didn't invent periods any more than he invented countries or states or counties, so take the 1450s as a very vague time when certain changes slowly began to take place. And in the same way well-known historians are invited, every decade or so, to look back and out of their great wisdom pick out certain turning points in history. What I'm saying, as a grateful pupil of the late W I Curnow, is that the historians are as much at sea as the rest of us, at the time, because all history is hindsight.
Historians too are victims of the big headlines.
For instance, I'm sure that most of them would say one of the great turning points of modern history was the dropping of the first atomic bomb. I have another historic turning point about that. It's a letter, sent in a hurry across the Atlantic in the early summer of 1939, from a young German woman, a Hitler refugee living in Sweden, who wrote to three extremely obscure Hitler refugees in New York. She was a crack radium researcher and the obscure ones were physicists. Don't be embarrassed by this item.