In the heart of the land of Canaan, the hebrew patriarch Abraham circa 2000 b.c. came to visit and be blessed by the priest of righteousness Melchizedek at Salem in the mountains of what later would be called the mountains of Judea. At that time the nation of Israel was still in the loins of Abraham and Sarah, and nearby was Mount Moriah where Abraham would offer Isaac as sacrifice ‘though replaced by the lamb which the Lord then provided for sacrifice instead, foreshadowing the sacrifice of the Lamb of God there 2,000 years later.
The king and priest of Salem was probably Shem, a son of Noah and distant ancestor of Abraham, Shem still alive ‘though circa 2000 b.c. because he lived (due to longer telomeres) for five hundred years after the flood, having brought the holy Word of God to his progeny (see http://genesisveracity.com/Articles/Article13.htm), hence Abraham considered him the priest of righteousness, the one to bless him as he would catch the vision that the land of Canaan would become Israel.
Five hundred years later, at the time of Moses, the Egyptians were referring to the city as Uru Salem, the city of peace, a remembrance no doubt of the time when Shem ruled there in righteousness with the cities of the barbarous Canaanites living all around, but at the time of Moses, the Canaanites had long since taken over, the city at that time known to them as the city of Jebus, named after their patriarch who had been a son of Canaan (see Genesis 10).
The climate began to change circa 1500 b.c. (just ask Harvey Weiss at Yale), then the Exodus of the Jews out of Egypt, who came to take the Holy Land as Abraham had prophecied. So because of that drastic climate change with the end of the Ice Age, the great lowland cities of the Canaanites turned to desert, the highlands of cities such as Jerusalem then becoming prime real estate, where David and Solomon would later practice irrigation from a system of cisterns. Read more about the real ancient world at http://genesisveracityfoundation.com.