According to biblical history and archeology, Exodus never happened and the Jewish people are pretty much just descendants from canaanites.
At the same time we know that the canaanites experienced a genocide at the hands of the "chosen people" (also canaanites). This is justified in the Bible because its something that God ordered (I will not expand on this), and to this day discussions on the morality of this are kept under-wraps.
The genocide of the canaanites included men, women and children, every caananite that wasn't part of the "chosen people" were exterminated.
In short, the first genocide (holocaust) experienced by the jewish people (canaanites) was at the hands of fellow Jewish people.
I will not cite sources, instead I encourage you to seek-out books by biblical scholars, and biblical archeologists. If you need a name, Bart Ehrman is always a good start.
Do with this information what thou wilt.
--Khajiit.