See Inside The First World War

1 Outbreak
The assassination of the heir to the throne of Austria-Hungary on June 28, 1914 led to Austria-Hungary declaring war on Serbia. France and Russia supported Serbia. Germany, an ally of Austria-Hungary, sent its army through Belgium in August 1914 to attack France. This led to Britain, who had a pact with Belgium, to declare war on Germany. Powerful guns that could fire explosive shells over long distances were used by armies on the battlefield.

2 Digging in
By the end of 1914, the new battleground was called the Western Front. Trenches were dug by both sides to defend their positions. The battleground stretched from the North Sea to Switzerland. Some of the heaviest fighting took place in Northern France and in Flanders, an area of Belgium.

3 Over the top
Allied army leaders ordered their soldiers to go 'over the top' and attack enemy trenches. The Allied army leaders believed that several of these attacks would wear down their enemies. These attacks failed to break the deadlock on the Western Front. The bloodiest battle was the Battle of the Somme were nearly a million soldiers were killed or wounded.

4 Warships
British and German navies battled each other for control of the oceans. Their fleets included powerful 10-gun dreadnoughts, speedy battle cruisers and smaller destroyers. On May 31, 1916, both British and German navies clashed in the Battle of Jutland which ended in a stalemate. On May 7, 1915, a German submarine sank a luxury liner carrying passengers some of which are Americans. This led to many Americans calling for the USA to enter the war.

5 In the skies
By 1916, fighter planes were used in combat over the Western Front. Most fighter planes had two wings and were called 'biplanes'. A pilot who shot down five enemy places was known as an 'ace'. The most famous air ace was a German known as the Red Baron. Other aircraft used in the war included German airships called zeppelins which were massive balloons powered by engines and propellers.

6 The War Spreads
By October 1914, the Ottoman Turks became involved in fighting in the war. In 1915, the Allied troops tried to capture the Gallipoli peninsula but were fought off by the Turkish forces. From 1916. Arab fighters helped the British fight against the Turks in the Middle East. Russian soldiers fought against the Central Powers in Eastern Europe. In Africa, Indian troops fought for the British and clashed with German soldiers. On April 6, 1917, the USA entered the war and joined the Allies.

7 To the end
The USA's entry to the War gave the Allies troops and tanks. The most effective tank of the First World War was the British Mark V. On August 8, 1918, the Allies attacked German trenches near the town of Amiens with 400 tanks. The attack overwhelmed the German soldiers and around 16,000 of them surrendered.

8 Final shots
By 1918, the Allies had won the war with victories in Europe and the the Middle East. On June 1919, leaders of 32 nations came together in France to sign a peace treaty. The Germans were made to pay huge sums of money and accept the responsibility for starting the war.