Countries Involved In World War 1

World War I was a global war that was started in Europe on July 28, 1914. This war lasted for over four years, finally coming to an end on November 11, 1918. This war was not only long, but it was also one of the largest wars in history. Over 70 million military personnel were mobilized – including 60 million Europeans.

This war was also very deadly, resulting in the death of approximately 9 million servicemen and 7 million civilians.

The first event that led to the war was the assassination of Archduke Franz Ferdinand by Gavrilo Princip. Following the assassination, Serbia and Austria-Hungary went to war. The war grew as a result of interlocking alliances. Europe was divided into two coalitions: the Triple Alliance and the Triple Entente. Then, a domino effect began. Russia was ready to defend Serbia, its ally. Then, Germany declared war on Russia in order to protect Austria. France in turn declared war on Germany to protect Russia. Then, Britain declared war on Germany after the Germans invaded Belgium.

The war finally came to an end in 1917 with the signing of the Treaty of Versailles.

On one side, the countries that were involved in this war included:

  • Austria-Hungary
  • Bulgaria
  • Germany
  • Ottoman Empire

Fighting against them were the following nations:

Rank Flag Name Population 2019 Area Area (mi²) % of Earth's Area Growth Rate Region Subregion
1United States329,064,9179,372,610 km²3,617,827 mi²6.31%0.60%AmericasNorthern America
2Russia145,872,25617,098,242 km²6,599,921 mi²11.52%0.09%EuropeEastern Europe
3Japan126,860,301377,930 km²145,881 mi²0.25%-0.27%AsiaEastern Asia
4Germany83,517,045357,114 km²137,846 mi²0.24%0.47%EuropeWestern Europe
5France65,129,728551,695 km²212,954 mi²0.37%0.21%EuropeWestern Europe
6Italy60,550,075301,336 km²116,316 mi²0.20%-0.13%EuropeSouthern Europe
7Romania19,364,557238,391 km²92,019 mi²0.16%-0.73%EuropeEastern Europe
8Hungary9,684,67993,028 km²35,909 mi²< 0.1%-0.24%EuropeEastern Europe
9Austria8,955,10283,871 km²32,374 mi²< 0.1%0.72%EuropeWestern Europe