Answer:The war was fought between two powerful groups. The opposing sides were: Germany, Austria-Hungary and their allies, including Bulgaria. Great Britain, France and Russia who were known as 'The Triple Entente'.
Explanation:
Long before the war began, the countries in these groups had made arrangements to work together and help one another if there was a war.
So when war did break out in 1914, parts of Europe was already divided into two sides.
Each of the countries involved got their troops ready to fight. Troops were groups that fought together and included both the army and the navy.
The war saw lots of battles take place in different countries, especially France and Belgium. Later, many other countries also become involved, some on the side of the Triple Alliance and others of the side on the Triple Entente.
Causes of the war
There was no single event that caused World War One (WW1). War happened because of several different events that took place in the years building up to 1914.
Firstly, there was the role of empire. Great Britain, Germany, Austria-Hungary and Russia all had empires. This meant that they ruled many countries all over the world.
Each of these countries wanted to keep their empire strong and was afraid of other countries taking over new territories. They saw this as a threat to their own empires.
So when Germany and Austria-Hungary took control of smaller countries like Bosnia and Morocco, it looked to the rest of the world like they were being aggressive.
Secondly, many countries had made alliances with one other. They agreed to protect one another. This meant that if one country was attacked, the others would get involved to defend that country.
However, the trigger for the beginning of WW1 occurred on 28 June 1914.
Archduke Franz Ferdinand, the heir to the throne of Austria-Hungary, was shot while he was visiting Sarajevo in Bosnia. He was killed by a Serbian person, who thought that Serbia should control Bosnia instead of Austria. Because its leader had been shot, Austria-Hungary declared war on Serbia.
As a result:
Russia got involved because Russia had an alliance with Serbia.
Germany then declared war on Russia because Germany had an alliance with Austria-Hungary.
Britain declared war on Germany because of its invasion of neutral Belgium - Britain had agreements to protect both Belgium and France
