Seventy years ago today, on the 22nd of June 1948, the Empire Windrush docked at Tilbury with several hundred Jamaicans on board. Thus began something quite unprecedented in all of our history – the displacement of the native population of these islands, hitherto entirely representative of the human stocks of north western Europe, by peoples of quite alien origin. What was then “a cloud no larger than a man’s hand” now overshadows the whole sky…