During World War I, the German Empire was one of the Central Powers. It began participation in the conflict after the declaration of war against Serbia...

between 1914 and 1918. When World War I started, Polish territory was split during the partitions between Russian Empire, the German Empire and Austria-Hungary...

Станислав Кельнер History of Germany during World War I Hungary in World War I Invasion of Serbia by Bulgaria during the First World War Salzburg Negotiations...

Technology during World War I (1914–1918) reflected a trend toward industrialism and the application of mass-production methods to weapons and to the technology...

was a leading Allied Power during the First World War of 1914–1918. They fought against the Central Powers, mainly Germany. The armed forces were greatly...

see Diplomatic history of World War I. Below is a table showing the outbreaks of wars between nations which occurred during World War I. Indicated are...

Australia, the outbreak of World War I was greeted with considerable enthusiasm. Even before Britain declared war on Germany on 4 August 1914, the nation...

Germany entered into World War I on August 1, 1914, when it declared war on Russia. In accordance with its war plan, it ignored Russia and moved first...

During World War I and World War II, Switzerland maintained armed neutrality, and was not invaded by its neighbors, in part because of its topography,...

At the onset of World War I, Vietnam, nominally under the Nguyễn dynasty, was under French protectorate and part of French Indochina. While seeking to...

military history of Canada during World War I began on August 4, 1914, when the United Kingdom entered the First World War (1914–1918) by declaring war on Germany...

Japan participated in World War I from 1914 to 1918 as a member of the Allies and played an important role against the Imperial German Navy. Politically,...

The Kingdom of Bulgaria participated in World War I on the side of the Central Powers from 14 October 1915, when the country declared war on Serbia, until...

diplomatic history of World War I covers the non-military interactions among the major players during World War I. For the domestic histories of participants...

outset of World War II did not specifically forbid the aerial bombardment of cities – despite the prior occurrence of such bombing during World War I (1914–1918)...

China participated in World War I from 1917 to 1918 in an alliance with the Entente Powers. Although China never sent troops overseas, 140,000 Chinese...

The use of slave and forced labour in Nazi Germany (German: Zwangsarbeit) and throughout German-occupied Europe during World War II took place on an unprecedented...

During World War I (1914–1918), Brazil initially adopted a neutral position. They did this in accordance with the Hague Convention, in an attempt to maintain...

neutral throughout World War I between 28 July 1914 and 11 November 1918, and despite domestic economic difficulties, it was considered "one of the most important...

to an unprecedented degree. All of the powers used lessons from their experiences on the home front during World War I. Their success in mobilizing economic...

The economic history of World War I covers the methods used by the First World War (1914–1918), as well as related postwar issues such as war debts and reparations...

The military history of the United Kingdom in World War II covers the Second World War against the Axis powers, starting on 3 September 1939 with the...

During World War I (1914–1918), belligerents from both the Allied Powers and Central Powers violated international criminal law, committing numerous war...

between 10 and 11 November 1918. At the start of World War I, King Carol I of Romania favored Germany, while the nation's political elite favored the...

of Liechtenstein into Germany. The leaders were almost immediately arrested and the hoped-for German invasion failed to materialise. During World War...

The German occupation of Belgium (French: Occupation allemande, Dutch: Duitse bezetting) of World War I was a military occupation of Belgium by the forces...

from the start of World War I in 1914 until early 1916. However, in that year and a half there were many hostile engagements between Germany and Portugal...

following its long-standing policy of neutrality since the Napoleonic Wars, remained neutral throughout World War I between 28 July 1914 and 11 November...

The total number of military and civilian casualties in World War I was about 40 million: estimates range from around 15 to 22 million deaths and about...

during World War I (28 July 1914 – 11 November 1918) was principally carried out by the United Kingdom and France for the Entente Powers and Germany for...