It was on 9th May 1945, that the II World War ended with the surrender of Nazi Germany to the Allies viz. USSR, Britain and US. The II World war started with the invasion of Poland by Hitler of Germany on 1st September 1939. The attack extended to France, Britain, USSR etc. Germany was joined by Italy and Japan which was called the Axis forces. On the other side Britain, USSR and Britain combined was called the Allies.
The Second World War ( 1939 – 1945) was the biggest and most disastrous war the world has ever seen. More than 30 countries were involved in the war with more than 100 million military in action. It is stated that 50-75 million people were killed during the war period including civilians. Almost 60% of the young people in the Europe was either killed or disabled. Lakhs of Indians fought in the British Army in foreign countries and lost their lives. US used the Atom bomb/Hydrogen bomb in Japan for the first time causing death of thousands of people and devastation of two entire cities.
The India Gate in New Delhi is a Memorial for the war heroes. Such war memorials are there in almost all countries where the II World War had spread. I have seen such War Memorials / cemetaries in Kohima (Nagaland) and Cambridge, where thousands of graves are built with the names of the war heroes.
The war changed the political map of the world. Many countries, including India, got freedom in the post-war period. The British lost most of their colonies. The United Nations was formed to stop any such war in future.
Let us hope that never in future such horrible wars take place.