World War I began in 1914 after the assassination of Archduke Franz Ferdinand of Austria-Hungary by a Serbian nationalist. This caused a series of military alliances to take sides in the war, dividing Europe into the Allied and Central Powers. Trench warfare dominated the Western Front as both sides engaged in brutal battles along miles of fortified trenches. Conditions in the trenches were terrible, with soldiers facing constant dangers from artillery fire, machine guns, poison gas, disease, vermin, and more. Over time, new weapons like tanks and airplanes were introduced, but the war remained deadlocked for years until the Allied powers prevailed in 1918.