Nobody has counted the earlier cases of genocide. One of the best known was the killing of about 1.2 million Armenians in 1915-17 and 1920-22 by the Turkish government. It had some features in common with the later Jewish Holocaust. I don't wish to offend Americans, but it's surely also the case that there was widespread genocide in much of North American against the Native Indian population - and also against many native tribes by the Spaniards in Latin America, too. I'd also add the appalling slaughter of an estimated 5 million natives in the Congo between about 1885 and 1908, when the so-called "Congo Free State" was the personal property of the king of Belgium. After the Belgian parliament took it away from him and turned it into regular colony there was an improvement in conditions. A distinctive feature of the Jewish and Armenian holocausts was their frenzied impatience and their utter relenentlessness.
The Holocaust was never really over. There are Holocausts happening right now in Iraq and other places of the world.
All over the world
the word that you are looking for is genicide(s), the Holocaust was a singular event, not the description of a type of event.
Just before the Holocaust there were about 18 million Jews world wide, and about one third (33%) were killed in the Holocaust.
There was only one Holocaust, there were a few attempted genocides, but the Holocaust is a specific term and cannot be used to describe other similar events.
over sixmillion Jews died in the holocaust
WW2 started before the Holocaust.
Jack Fischel has written: 'The Holocaust' -- subject(s): Holocaust, Jewish (1939-1945), Jewish resistance, World War, 1939-1945 'Holocaust Studies Annual'