World War I (1914-1918)

Central Powers – Mainly Germany, Austria-Hungary, and Turkey
Allied Powers – Mainly France, Great Britain, Russia, Italy, Japan, and, from 1917, the United States.

Expansionist Policy of the German – German Emperor Wilhelm II adopted a policy to make Germany a world power. It was seen as a threat by others who stabilized the international situation.
Militarism – The rising Nationalist sentiments within nations created tension between the powers which in turn resulted in a sense of insecurity and fear. Eg. Naval race between Britain and Germany.
Imperial Greed – Powerful nations began searching for new colonies to satisfy their greed as a result competition to capture the colonies increased.
Immediate Cause – Assassination of Archduke Franz Ferdinand (Heir to the throne of Austria-Hungary). Subsequent events that followed are :
- Austria-Hungary declared war on Serbia.
- Russia got involved as it had an alliance with Serbia.
- Germany had an alliance with Austria-Hungary and they declared war on Russia.
- Britain came into the scene against Germany as the former was aligned with Belgium and France.

Political
- The fall of the Russian Empire and the formation of the USSR, and the USA grew as a superpower.
- Spread of democracy- end of European supremacy, end of royal dynasties in Russia, Germany, Austria, Hungary, and Turkey.
- Strengthened independence movement in Asia and Africa.
Economic
- European industries collapsed
- Rising inflation, poverty, and unemployment
Social
- Women replaced men in factories
- Impetus to socialist ideas
- Softening of racial problems.

On June 28, 1919, World War 1 officially ended with the signing of the Treaty of Versailles.

Approximately 13 lakh Indian soldiers participated in the World War 1
- Key Event – The Lancer division of princely states of Jodhpur and Mysore participated in the Battle of Haifa – 1918 which was fought between British forces and Ottoman forces
India supplied war equipment and wealth required for the war

Ending the myth of Indestructible European power, the morale of the Indian soldiers increased.
Domestic manufacturing sectors such as cotton benefited from the decline in British goods that had dominated the pre-war market.
The launch of the Non-Cooperation Movement was impacted by the World War.
The formation of the USSR after the war resulted in the formation of the Communist Party in India.