Nationalism was an especially strong force in Europe’s Bakan Peninsula, where several nationalist groups had won their independence from the Turkish ottoman empire.
Germany sought an alliance with Austria-Hungary and Russia
Germany created the Dual Alliance under which Germany and Austria-Hungary agreed that each other would help if one was under attack
Italy joined Germany and Austria-Hungary with became a Triple Alliance
Britain signed the Entente Cordiale with France
Britain and Russia settled their differences and they both linked up with France in a Triple Entente.
Britain declared war on Germany and Australia was part of the British Empire and therefore was also at war
Italy withdrew from the Triple Alliance and joined the Allies
The first landing of soldiers on the beaches of Gallipoli took place.
The First Battle of the Somme began.
The United States of America joined the Allies.
Russian’s military was collapsing and the Revolution ended Russia’s involvement in the war
Australia made the first large Allied attack
The end of the fighting on the Eastern Front enabled Germany to move many more troops to the Western Front.