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.
Around 17 million soldiers and civilians were killed during WW1. Although more Britons died in WW1 than any other conflict, the bloodiest war in our history relative to population size is the Civil War, which raged in the mid-17th Century. A far higher proportion of the population of the British Isles were killed than the less than 2% who died in WW1.