The UN was started in 1945, just after World War II.
It was the assasination of archduke franz Ferdinand that directly started world war 1
The big one was Germany's invasion of Poland, that kind of kicked it off, but China and Japan were fighting the war with each other first.
The invasion of Poland
It was Germany's invasion of Poland that began World War II.
World War One started.
Germany invaded Poland
The assassination of Archduke Ferdinand
The assassination of Franz Ferdinand
Many events led to world war1 but the main event that started the war was when archduke Franz Ferdinand of austria-Hungary was assassinated by a serbian terrorist Many events led to world war1 but the main event that started the war was when archduke Franz Ferdinand of austria-Hungary was assassinated by a serbian terrorist
Germsny invaded Poland in 1939.
The assassination of Arch Duke Franz Ferdinand.