The instability created in Europe by the First World War
(1914-18) set the stage for another international conflict–World
War II–which broke out two decades later and would prove even
more devastating. Rising to power in an economically and
politically unstable Germany, Adolf Hitler and his National
Socialist (Nazi Party) rearmed the nation and signed strategic
treaties with Italy and Japan to further his ambitions of world
domination. Hitler's invasion of Poland in September 1939 drove
Great Britain and France to declare war on Germany, and World
War II had begun. Over the next six years, the conflict would
take more lives and destroy more land and property around the
globe than any previous war. Among the estimated 45-60 million
people killed were 6 million Jews murdered in Nazi concentration
camps as part of Hitler's diabolical "Final Solution," now known
as the Holocaust. More to Explore People and Groups This Day in
History World War II On this day in 1944, in what would become
known as the "Marianas Tur