Blutmai
Blutmai (English: Bloody May, lit. 'Blood May') was an outbreak of political violence that occurred in Berlin from 1 to 3 May 1929. It occurred when the Communist Party of Germany (KPD) held May Day marches in defiance of a ban on public gatherings in Berlin ordered by the city's police chief Karl Zörgiebel of the Social Democratic Party (SPD).