The New Zealand Expeditionary Force (NZEF) was the title of the military forces sent from New Zealand to fight alongside other British Empire and Dominion troops during World War I (1914–1918) and World War II (1939–1945). Ultimately, the NZEF of World War I became known as the First New Zealand Expeditionary Force. The NZEF of World War II was known as the Second New Zealand Expeditionary Force (2NZEF).