It divides neatly into two parts -- Eastern and Western. The Eastern Hemoclysm began with the overthrow of the Manchu dynasty in China in 1911 leading to 38 years of Civil War and a Japanese invasion. In 1949, the bloodbath of the interregnum gave way to a greater bloodbath as the Communists consolidated power under Mao (who died in 1976). When seen as a continuum, this phase of Chinese history was a 65 year nightmare which took some 75 million lives.

The first sparks of the Western Hemoclysm were the Balkan Wars (1912-13) which quickly ignited the First World War. This brought down four of the most powerful monarchies in Europe, leading to a power vacuum which was eventually filled by the Nazis in Germany and the Communists in Russia, who came into conflict during the Second World War. The death of Stalin in 1953 finally extinguished the Western Hemoclysm after the loss of some 80 million lives.

If it weren't for the fact that the Second World War is considered to be a single event, we could probably consider the Eastern and Western halves of the Hemoclysm to be distinctly unrelated pieces of history.