What event brought on the beginning of world war ii in europe?

When Germany demand Danzig from Poland but Poland refused so Germany declared war on them in 1939.

In an unlikely and brief alliance, the Soviet Union and Germany invaded Poland on September 1, 1939, and that caused the beginning of World War II in Europe. 

Good luck :)

Cherokee  removal, part of the trail of tears, refers to the  forced  relocation between 1836 and 1839 of thecherokee  nation from  their lands ingeorgia, south carolina, north carolina, tennessee, texas, and alabama to the indian territory (present day oklahoma)  in  the thenwestern united states, and the resultant deaths