The document summarizes several major battles of World War 1, including the Battle of Tannenberg between German and Russian forces in 1914, the lengthy and devastating Battle of Verdun between German and French armies from 1916-1917, and the massive Battle of the Somme in 1916 that resulted in over 1 million casualties for British, French and German forces. It also discusses the 1914 Battle of the Marne that stopped the initial German offensive, the failed Gallipoli Campaign by British and French forces against the Ottoman Empire, trench warfare stalemate on the Western Front, and the Christmas Truce of 1914 when opposing troops briefly ceased fire to celebrate the holiday together.