The First World War, otherwise known as the Great War, began in July of 1914 after a Yugoslav militant assassinated Archduke Franz Ferdinand of Austria-Hungary. Shortly after, Austria-Hungary declared war on Serbia.
I hope this pays off...
I hope I don't get shot down...
The war grew when Russia, honoring its obligations to other Slavic nations, declared war on Austria-Hungary. Shortly afterwards, Germany declared war on Russia, and the United Kingdom and France declared war on Germany, making the Austro-Serbian conflict a true world war.
Submarine, over there!
The war on the ground was brutal and devolved into static trench warfare, as advances in weaponry couldn't catch up to advances in transportation. Thousands of men died in frontal assaults on enemy trenches, often only gaining a few meters or kilometers of ground in an offensive.
The end. Robert Lazar Period 4
One form of transportation that did advance, however, was the airplane. Dogfights, aerial bombing, and other forms of combat in the air came into existence as planes became sturdier, larger, and faster.
The war at sea was mostly kept underwater, as the newly-invented submarine proved a terror to both Allied and Central shipping. German U-boats became synonymous with the term "submarine" as their advanced fleet of hunter-killer subs sunk millions of tons of shipping. A major U-boat incident was the sinking of the RMS Lusitania, in which an apparently-unarmed passenger ship was sunk off Ireland by a U-boat. Among the dead were Americans, and the incident would eventually contribute to the USA entering the war.
The First World War ultimately resulted in millions of deaths from many nations, and led to wide-reaching consequences for the world as a whole. The war ended on November 11th, 1918, when the German Empire signed an armistice in a rail car. The later Treaty of Versailles would contribute to the Second World War, and the effects of the war on nations such as France and the UK created a "lost generation."