The Holocaust, referring to the persecution and attempted extermination of Jewish people throughout Europe by the NAZI German forces under orders of Hitler began shortly after Hitler was made Chancellor of Germany, then confiscated guns from the citizens.
It ended essentially with the defeat of NAZI Germany by the combined Allied forces.
Meanwhile another extermination of the Jewish people was ongoing throughout Russia and several surrounding (and subservient) nations.
Hitler’s efforts killed appx 6 million Jews.
Stalin exterminated over 20 million.
The Russian extermination programs started before WWI…. but nobody has even tried to estimate the numbers killed before Stalin.
The Musical and later Movie: “Fiddler on the Roof” is set in a time appx 20 to 30 years before WWI. You’ll notice no automobiles… the police and troops used horses. This shows a little of the Russian “pogroms” to drive out or murder the Jewish people.
In a way, the attempted extermination of the Jewish people continues today… The constant attacks on the current nation of Israel by Palestinians, the assorted major attacks on Israel since the relocation of Jewish refugees to the traditional Jewish homeland.
And the blatant antisemitism that appears to be one of the forms of discrimination that is considered to be perfectly normal in USA RIGHT NOW. Its even considered stylish to be anti-Semitic in some areas…
You could say that the Holocaust has been ongoing since more than 2000 years BC. Clear back to the time of the Biblical Exodus.