WWI: Who?

Who was the one who caused WWI, who was involved, and who won? On June 28, 1914 a group of assassins from The Black Hand attempted and succeeded in assassinating Austria-Hungary's Archduke Franz Ferdinand. As we would later find out, these terrorists were funded by Serbia. This was because Serbia wanted to weaken the Austrio-Hungarian government so that Serbia could take back a large portion of land that they had taken from Serbia. This land was known as the Balkans and was majorly centered around Bosnia, and it was soon to be the cause of WWI. As Austria-Hungary looked to retaliate on Serbia, Serbia looked to its ally Russia in helping them defend themselves. Russia then called upon its allies in France and Great Britain. When Austria-Hungary heard of this, they too called upon their ally in Germany who then called on its ally in Italy. Eventually on July 29, 1914 Russia mobilized its troops, this was considered an act of war in those times, and WWI began when Germany declared war on Russia. Four bloody and brutal years later the conflict came to an end with Britain and its allies winning.