Czar Nicholas II and his wife. After Revolution of 1905 he failed to solve Russia's basic political, economic and social problems, this sparked eruptions. March 1917 the first of two revolutions toppled the Romanov dynasty and started more radical changes.
Bloodiest War in American History: Not the Civil War -- World War Two. Although more American died in the Civil War, more Americans were killed in WW2. It's a pedantic technicality perhaps, but the Civil War was America's deadliest war, World War II its bloodiest.
Bloodiest single day of battle in the Civil War. Gen. McClellan had found a copy of Gen Lees battle plan that he left at a abandoned Confederate camp and learns that Lee had divided his army so McClellan and Gen Lee met on the Antietam Creek which was the single bloodiest battle in US history.