They are descendants of Ham. From Canaan naturally came the Canaanite clans - Sidon, Hittites, Jebusites, Amorites, Girgashites, Hivites, Arkites, Sinites, Arvadites, Zemarites and Hamathites. (Genesis 10:15). According to the Bible account, "Later the Canaanite clans scattered and the borders of Canaan reached from Sidon toward Gerar as far as Gaza, and then toward Sodom, Gomorrah, Admah and Zeboiim, as far as Lasha." (Genesis 10:19). It's in this described area that the conflict between the Israelites and the "peoples of the land" began, and has continued right to the present day.
When I said mystery I meant their arrival in the Levant.
Their villages with distinctive archeological relics just start appearing in the ground records without any previously known evolution from a prior race or civilization.
I have no problem with the Biblical record since so many of the written tales are provable with archeology. But,If you believe they are the tribe of Ham, then where were they during those previous millenia?