Note that on numerous occasions hostilities were assumed without a formal declaration, e.g. Russia with Germany and Austria-Hungary in August 1914.
- Australia. Entered war together with Britain on 4 August 1914.
- Austria-Hungary. Declared war with Serbia on 28 July 1914.
Regarding this, which countries were involved in First World War?
Germany was joined by Turkey and Bulgaria. The Allies were joined by Italy, Japan, Greece, Portugal, and Romania. Later on, in 1917, America entered the war on the side of the Allies. Spain, Switzerland, Albania, the Netherlands, Denmark, Norway, and Sweden all remained neutral in the First World War.
Who fought in World War One?
World War I began in 1914, after the assassination of Archduke Franz Ferdinand, and lasted until 1918. During the conflict, Germany, Austria-Hungary, Bulgaria and the Ottoman Empire (the Central Powers) fought against Great Britain, France, Russia, Italy, Romania, Japan and the United States (the Allied Powers).
What countries were involved in World War 1 and 2?
World War 2 was fought between two groups of countries. On one side were the Axis Powers, including Germany, Italy and Japan. On the other side were the Allies. They included Britain, France, Australia, Canada, New Zealand, India, the Soviet Union, China and the United States of America.