t’s hard to believe that a hundred years ago, one of the most deadly world wars ever took place. The 1914-1918 conflict shattered the Austro-Hungarian, Ottoman and Russian empires, killed 16 million military personnel and civilians, and changed the map of Europe. It also introduced the horror of trench warfare, lethal new weapons including poison gas and tanks, and brought the United States into international politics as a major player.

The underlying cause of the war was imperialism. Many countries wanted to expand their territories, grabbing land from smaller countries as they competed to become the most powerful nation in Europe. This caused tension and rivalry between nations.

Alliances were also important. Large European powers formed a network of alliances to prevent a big war. This meant that if Austria-Hungary or Germany started a war, they would pull in their allies. This made the conflict much bigger than the two enemies that started it.

Finally, nationalism was another factor in the war. This was a growing trend that encouraged people to decide where their loyalty lay based on ethnic or cultural background rather than shared interests or ideals. It was a major reason for the assassination of Archduke Franz Ferdinand of Austria, which led to the war.

In the field, the stalemate of trench warfare began to break down as the Allied forces won victories in North Africa and eventually converged near Tunisia. Soldiers suffered from the effects of malnutrition, cholera and typhoid fever. They also struggled with the muck of “No Man’s Land” and battled a variety of injuries, including trench foot and trench mouth. Amid all this, they were bombarded by artillery and machine gun fire, and attacked by infantry assaults, tank and early airplanes.