To understand how the Second World War began,
you actually have to go back to the end of the first.
In 1919, leaders of the countries which had fought in World War One
came together in France to sign a peace treaty.
It was called the Treaty of Versailles
and it officially blamed Germany for the war.
It forced it to make big repayments
and hand over control of some of its land.
It also banned it
from having armed forces.
The treaty had a huge impact on Germany,
which was already poor and struggling after the war,
and a lot of German people were angry with their leaders.
An up-and-coming politician tapped into that anger.
His name was Adolf Hitler.
Hitler was a convincing speaker and he won fans
talking about ways to restore Germany to its former glory.
He also spoke about his racist views and his hatred of Jewish people.
In 1933, Hitler became Germany's chancellor.
His Nazi Party soon changed the way the country was run
and Hitler started calling himself Fuhrer,
or Supreme Leader.
(SHOUTS IN GERMAN)
He was obsessed with the idea of a pure German race,
which he called Aryan,
and he wanted that race to control all of Europe.
Hitler started secretly building up the German Army.
Then, in 1938, the Nazis invaded Austria.
At first, other European countries,
which were still recovering from the last war,
did not really react.
In fact, some signed agreements with Germany to stay peaceful.
But that changed on 1 September 1939 when the Nazis invaded Poland.
MAN: The Mad Dog of Europe has at last plunged civilization
into a new world war.
Britain and France and their allies declared war on Germany
and later its allies, which included Italy and Japan.
The fighting spread across the globe.
In 1940, France fell to the Nazis
and more countries joined the fighting.
In 1941, Japan bombed Pearl Harbor, a US naval base in Hawaii,
bringing America into the war.
That same year, the Soviet Union - a group of states including Russia -
had joined the fight against the Nazis.
Meanwhile, in Germany and German-occupied countries,
something really sinister was happening.
The Nazi regime was rounding up people
that didn't fit into its plans for an Aryan race.
Millions of people, most of them Jewish,
were killed in what's now known as the Holocaust.
For a while, it looked like Germany was actually going to win the war,
but a big turning point was D-Day when Allied forces carried out
the biggest ever land, air and sea mission
to take back Nazi-occupied Europe.
MAN: Adolf Hitler was presumably alive
until the last days of Berlin.
By the best evidence, he is now dead.
Just over a year later, Germany had surrendered.
The representative of the German High Command
signed the act of unconditional surrender.
Today is Victory in Europe Day.
(CHEERING)
While Europe celebrated, Japan hadn't surrendered...
..and in August 1945,
the US made the decision to drop two nuclear bombs on Japan,
with devastating results.
NEWSREADER: 126,000 died.
Japan surrendered
and the most destructive war in history was finally over.
It's not known exactly how many people died in World War Two,
but it's thought to be somewhere between 70 and 85 million.
The war changed the way the world looked.
The US and the Soviet Union became global superpowers
and the United Nations was founded
in the hope that another world war would never happen again.