World War Two in Europe began on 3rd September 1939, when the Prime Minister of Britain, Neville Chamberlain, declared war on Germany. It involved many of the world's countries
The Second World War was started by Germany in an unprovoked attack on Poland. Britain and France declared war on Germany after Hitler had refused to abort his invasion of Poland.
At 4:56pm on 7 September 1940, the air raid sirens wailed as the German Air Force, the luftwaffe, launched a massive raid on London. Over 350 bombers flew across the Channel from airfields in France and dropped 300 tonnes of bombs on the docks and streets of the East End of London.
As the night raids became so frequent, many people who were tired of repeatedly interrupting their sleep to go back and forth to the shelters, virtually took up residence in a shelter.
Evacuation means leaving a place. During the Second World War, many children living in big cities and towns were moved temporarily from their homes to places considered safer, usually out in the countryside.