The World War II Portal
World War II, or the Second World War, was a global military conflict. It began as the joining of what had initially been two separate conflicts, with the first beginning in Asia in 1937 (the Second Sino-Japanese War) and the other beginning in Europe in 1939 (the German and Soviet invasion of Poland).
The war split the majority of the world's nations into two opposing military alliances: the Allies and the Axis. It involved the mobilization of over 100 million military personnel, making it the most widespread war in history, and placed the participants in a state of "total war", which erased the distinction between civil and military resources and resulted in the complete activation of a nation's economic, industrial, and scientific capabilities for the purposes of the war effort. Over 70 million people, the majority of them civilians, were killed, making it the deadliest conflict in human history.
The Allies won the war, and as a result, the Soviet Union and the United States emerged as the world's leading superpowers. This set the stage for the Cold War, which lasted for the next 45 years. The United Nations was formed in the hope of preventing another such conflict. The self-determination spawned by the war accelerated decolonization movements in Asia and Africa, while Europe itself began moving toward integration.
The Enigma machine
was a cipher machine
used to encrypt
and decrypt secret messages. More precisely, Enigma was a family of related electro-mechanical rotor machines
, comprising a variety of different models.The Enigma was used commercially from the early 1920s on, and was also adopted by the military and governmental services of a number of nations—most famously by Nazi Germany
before and during World War II
.The German military model, the Wehrmacht Enigma
, is the version most commonly discussed.The machine has gained notoriety because Allied cryptologists
were able to decrypt
a large number of messages that had been enciphered on the machine. Decryption was made possible in 1932 by Polish
cryptographers Marian Rejewski
, Jerzy Różycki
and Henryk Zygalski
from Cipher Bureau
. In mid-1939 reconstruction and decryption methods were delivered from Poland
. The intelligence
gained through this source, codenamed ULTRA
, was a significant aid to the Allied war effort.