World War I was a war that was fought between countries in Europe. It was a huge conflict that killed over 9 million people and changed the world.

World Wars have been a big part of history, and it is important to learn about them. This is because they helped shape the world as we know it today.

Alliances:

In the 19th century, many of the European countries were making alliances to protect each other in case they needed to fight. This created a lot of tension and rivalry between the different countries.

Arming for War:

In the years before world war, many countries were spending a lot of money and energy to create huge militaries. This led to a need for bigger and more powerful weapons.

Nationalism:

In Europe, each country was trying to become the strongest and most powerful in the world. They also wanted to expand their empires.

Imperialism:

In this time, there were a lot of European countries that practiced imperialism to make their nations stronger and more powerful. This made them compete with each other, and it was a major reason for the war.

Germany and Britain were the two most powerful countries in Europe, and they both practiced imperialism. This caused a lot of tension between them, and the world had to be prepared for it.

The assassination of the Austrian Archduke:

On July 25, 1914, the heir to the throne of Austria-Hungary and his wife were murdered in Sarajevo by Serbian nationalists. This assassination started the World War 1.