What Caused the First World War Simple History?

The First World War was a global conflict that lasted from 1914 to 1918. It was one of the deadliest conflicts in history, resulting in millions of deaths and significant changes in the political and social landscape of Europe.

But what caused this catastrophic event? In this article, we will explore the various factors that led to the outbreak of the First World War.

The Alliance System

One of the primary causes of the First World War was the alliance system that existed between European nations. In 1882, Germany, Austria-Hungary, and Italy formed an alliance known as the Triple Alliance. This alliance was created to counterbalance France’s growing military power.

In response, France formed an alliance with Russia in 1894 known as the Franco-Russian Alliance. Later on, in 1907, Russia joined forces with Britain and formed another alliance known as the Triple Entente. This alliance system created a sense of tension between these nations and made it easier for war to break out.


At this time, many European nations were expanding their empires around the world through colonization and imperialism. This resulted in competition for resources and territories, which increased tensions between these nations.

Germany’s desire for colonies led to conflict with Britain over control of Africa. The tensions between these two nations eventually led to an arms race as both countries tried to build up their military strength.


Nationalism also played a significant role in causing World War I. Many people felt a strong sense of pride towards their country and believed that it was superior to all others. This sense of nationalism fueled hostility towards other nations and made it easier for governments to justify going to war.

One example is Serbia’s desire for independence from Austria-Hungary. When Archduke Franz Ferdinand was assassinated by a Serbian nationalist in 1914, it led to a chain reaction of events that eventually led to the outbreak of World War I.


Militarism refers to the belief that a country should maintain a strong military presence and be prepared to use force when necessary. Many European nations at this time were investing heavily in their military, which further increased tensions between them.

Germany, in particular, had been building up its military strength for years and had the largest army in Europe. This made other nations nervous and contributed to the overall sense of unease and hostility between them.


In conclusion, the First World War was caused by a combination of factors, including the alliance system, imperialism, nationalism, and militarism. These factors created an environment of tension and hostility between European nations that eventually led to war. The impact of this conflict was felt around the world and changed the course of history forever.