this is another bit from one of my other history wikieducator pages

World War One
The First World War which was mostly called the World War or the Great War from 1914 until the start of World War 2 in 1939, was a major war centred in Europe that started on the 28th of July
1914 and ended on the 11th of November 1918. All the world's major powers at the time were involved, they were split into two groups the allies which was made up of the United Kingdom , France and Russia (until their revolution in October 1917 when the Bolsheviks who were communist took over) and then on April the 6th 1917 the USA joined World War One on the side of the allies, and the Central Powers who were made up of Germany, Austria-Hungry and later on in August with the signing of the Turco-German alliance the Ottoman Empire joined the Central Powers. These two groups got bigger as more nations entered the war.
During the course of the war more than 9 million soldiers were killed. This was mostly because of the great advances in firepower from previous conflicts and the lack of advances in mobility.
http://www.youtube.com/embed/ZVDUXPB_sTs