World War I
World War I was a war that many countries fought. It happened in different parts of the world, so it is called a "world" war. It lasted from 1914 to 1918. It was also called The Great War and The War to End all Wars. 135 countries took part in the war.
World War I was the first war where tanks and one of the first wars where aeroplanes were used and became very important. They also used underwater boats, called submarines.
The war started after Archduke Ferdinand of Austria, who many people thought would become King of Austria, was killed by Gavrilo Princip, a member of a Serbian terrorist group. This happened in Sarajevo in what is now Bosnia. But there are other reasons why the war started.
The countries of Europe were divided into two groups. They were like groups of friends who promised to help each other if one was attacked. If one country was attacked by an enemy country, their friend country had to join in the war between the two. Because of these agreements, as soon as one country was attacked, all the countries in Europe became part of the Great War.
There were two groups: the Allies and the Central Powers. The Allies were Russia, France, and Britain, and later Italy and the United States joined them. The Central Powers were Austria-Hungary, Germany, and the Ottoman Empire.
How it started
In the country of Austria-Hungary, there lived many people who spoke different languages. In the south, there was a group of people called Slavs who spoke very similar languages. Many of them thought they should live together in one country along with other Slavs outside of Austria-Hungary, in Montenegro and Serbia. One of these Slav parts was called Bosnia. The reason why the Slavs there wanted to be part of Serbia was that Bosnia had only been part of Austria-Hungary for a few years. Serbia and Bosnia were part of a bigger country before, which was called Turkey. But Serbia became its own country, while Bosnia became part of Austria-Hungary instead. This made a lot of people in Bosnia angry, especially the Slavs. A small group of young Slavs who lived in Bosnia decided that the south Slavs would need to kill before they would be allowed to live together in one country - they were terrorists. They called themselves "Young Bosnia". A group in Serbia who were called the Black Hand decided to help them.
Then, Franz Ferdinand, Archduke of Austria, came to Sarajevo, the most important city of Bosnia. Ferdinand's father was brother of the Emperor. Most people in Austria-Hungary thought he would become Emperor of Austria-Hungary in his uncle's place. The young Slavs of 'Young Bosnia' decided to kill him. Ferdinand was in his car when Gavrilo Princip went up to them. He shot and killed both Ferdinand and his wife on June 28, 1914.
The Austro-Hungarian government said this was a very bad crime. They blamed Serbia, because people there had helped 'Young Bosnia'. They asked Serbia to agree to a lot of things so that killings like that could be stopped. The Serbian government agreed with most of the things Austria-Hungary asked, but said there was one they couldn't agree to, because they were a different country. That was to shut all their newspapers down. The Austrians said they must agree to everything. Germany was Austria-Hungary's friend, so the Germans said that Austria-Hungary was right.
Serbia didn't agree to shut its newspapers down, so Austria-Hungary used this as an excuse to start a war on Serbia because like Bosnia before they wanted Serbia's land. Russia was Serbia's friend, and the Tsar (the Russian leader) decided to mobilize the Russian army. Mobilization is when many young men are told to join the army to fight an enemy and when a country makes many more machines used for war, like tanks, airplanes and shells used for bombing. The Kaiser (the German leader), mobilized Germany's young men also, because he wanted to help his friend, Austria-Hungary, and he made war on Russia. Germans knew that France was the friend of Russia, and that France would help Russia in a war, so they started a war on France too.
The reason why Germany told France and Russia that they were at war so quickly, was because they thought they could win the war if they attacked first and quickly. They could mobilize very quickly. They had a list of all the men who had to join the army, and where those men had to go, and the times of every train that would carry those men to where they would have to fight. France was doing the same thing, but could not do it as quickly.
Russia had a big army, but it would take a long time to mobilize their army, and a long time before they could attack Germany. The Germans decided to attack France quickly, while Russia was still not ready to attack them. They were afraid that if they waited and tried to talk with Russia and France, that they would not agree to peace. Then Russia would be ready to attack, and Germany would have to fight France and Russia at the same time.
There was also a time before where Germany had made war on France, sent its army in there, took France's most important city (Paris) very quickly and won the war. The Germans thought they could do it again easily, punish France and make them scared of Germany, which is another reason why they made war so quickly. This embarrassed France very much, and France was hoping to punish Germany like the Germans had done to France before.
Russia was very annoyed at Germany because Germany and its friends were annoying the Slavs who were related to Russians. Germany wanted Russian land around the Baltic Sea which Germany had owned a long time ago and the Russians were nervous that Germany would take away parts of their country where they made much money. The Germans thought the Russians were weak because of many reasons - Russia had lost many wars, the poor people in Russia were angry at the Russian leader and the army was not modern or new compared to Germany's.
Although it was friends with France and Russia, Great Britain did not go into the war quickly, but it decided to go to war against Germany when Germany attacked its important friend Belgium to get through to France. Britain had the biggest empire (parts of the world it ruled) and was afraid that Germany would take its and France's colonies and become the most powerful and biggest empire in the world. Britain was also worried about Germany's growing military power because Britain had the most ships (its navy) and a very big army for a long time. The Germans were quickly building ships and putting men in its army and Germany was almost going to become as powerful as Britain.
Both countries as well as Russia and France built up their navies and armies to be the best (called an arms race) before the war. Britain's king, Russia's Tsar and Germany's Kaiser ("Tsar" and "Kaiser" both mean "emperor" and come from the name of Julius Caesar) were all cousins but were not very friendly with each other.
Turkey went into the war because it had lost much of its empire before the war and wanted to get it back. It hated Serbia because Serbia became its own country before the war and took many Turkish lands. When Austria went to war against Serbia, Turkey did too.
Greece went into the war because it was a long time friend of Serbia. Serbia and Greece were free countries before Turkey took them hundreds of years before. Greece and Serbia became free again but a lot of Greek people still lived in Turkish lands which used to belong to Greece. The Greeks especially wanted their old important city of Constantinople back (now called Istanbul) where many Greeks lived and so the Greeks declared war on Turkey.
Bulgaria, like Greece and Serbia, was owned by Turkey before, got its freedom and took a lot of Turkish land. But when the Bulgarians did a short time before the war, the Serbians and Greeks felt cheated because the Bulgarians got a lot of land which they felt was Greek or Serbian. The Greeks and Serbians took back Bulgarian land and annoyed Bulgaria, which made Bulgaria to become friends with their old enemy Turkey. They declared war on Serbia and Greece.
Italy was on the side of Germany and Austria-Hungary at first, but changed sides when they thought Austria-Hungary was going to take land in northern Italy like it had done before.
Romania was a friend of Russia's and an enemy of Bulgaria, so they sided with the Allies.
Some important events in the war
Most people thought it would be a short war. They thought the armies would move around quickly to attack each other, and one would defeat the other without too many people getting killed. They thought the war would be about brave soldiers - they did not know what the war would really be like. Only a few people like Lord Kitchener said the war would take a long time.
Germany's generals had decided that the best way to defeat France was to go through Belgium. They would then be able to attack the French army the north side and the south side at the same time. The German Army went into Belgium on the 4 August. On the same day, Great Britain started a war on Germany, because Britain was a friend of Belgium. The British had said some time before, in 1839, that they would not let anyone control Belgium, and they kept their promise.
When the Germans got to the Belgian city of Liège, the Belgians fought very hard to stop them from coming into the city. The Germans did finally push the Belgians out of the city, but it had taken longer than the German generals had planned. Then the Germans attacked the north side of the French army. The French and the British moved men up to fight the Germans. They could do this because the Belgians had fought so long at Liège. But the Germans pushed the French and British back, until they were stopped at the river Marne.
In the fighting, many men had been killed. The new guns the men had fired very quickly. Some had machine guns, that fire so many bullets that the bullets fell like rain. So as not to get killed, the men on both sides took spades and dug holes. The holes joined up into trenches, until the lines of trenches went all the way from Switzerland to the North sea. In front of the trenches, there was barbed wire that cut anyone who tried to climb over it, and mines that blew up anyone who tried to run across the "no man's land" that was in between the trenches.
In the East, the Russians had attacked the Germans. The Russians pushed back the Germans, but then the Germans defeated the Russians at the Battle of Tannenburg. Then everyone in the East dug trenches, like in the West.
On Christmas day in 1914, many soldiers did not want to fight. They sang Christmas songs to each other. In many places on the Western front, they came out of the trenches and shook hands with each other. Sometimes they played football with each other. In some places, the men didn't want to fight again the next day. The generals were afraid and stopped this.
The machine guns and the trenches and mines made it very difficult to attack. The generals didn't understand this, and they still ordered attacks anyway. At the battle of the Somme in 1916 many British men died in a single day. It was one of the bloodiest days in the history of the British army.
Often many men died fighting over very small pieces of land.
In 1917, there was a revolution in Russia. The Tsar had to say he would not be Tsar any more, and that the people should have power. At first it was thought that Russia would fight harder now that the Tsar was gone. But the Russian people didn't want to fight anymore. They began to hate their new government because it wouldn't stop the war. Then there was an October Revolution, a second revolution in Russia led by Communists who followed the ideas of Karl Marx. The leader of the revolution, and of Russia, was then Vladimir Lenin. The new government asked for peace from the Germans. The Germans and Russians stopped fighting and signed the treaty of Brest-Litovsk, which gave Germany lots of land in Eastern Europe and the Baltic.
The German Generals decided to use submarines, underwater boats, to attack the ships that were carrying food and weapons to Great Britain. The Germans thought that the Americans were helping only the British and not being neutral. "Neutral" means that a country is not involved in the war. But some Americans were killed by the submarines. The United States then got in the war against Germany.
In the spring of 1918, the German generals decided they had to attack before many American soldiers arrived in Europe to attack them. The Germans attacked in a new way. They would attack where the Allies were weak, and leave alone the places where the Allies were strong. They pushed the British and French a long way in some places, but each time, the Germans were stopped. Then the Americans began to arrive. The British, the French and the Americans together began to push back the Germans. The Germans couldn't stop them. At last, the German generals told their government that the war had to be stopped, because Germany couldn't fight any longer. Germany asked for peace from the Allies, and the war ended on the 11th of November 1918.
After the War
After the war, the Germans had to agree to the Treaty of Versailles. Germany had to pay $33 billion. Part of the treaty said the countries of the world should come together to make an international organization to stop wars from happening, called the League of Nations. The US Senate didn't agree with this, even though it was the idea of the US president, Woodrow Wilson. Woodrow Wilson tried hard to tell the American people that they should agree, but the US never joined the League of Nations.