After the flood, God charged Noah and his sons to, “Be fruitful and multiply, and fill the earth.” He stated that man would have dominion over the animals of the earth. God also made a covenant with man that He would never destroy man and animals from the earth with a flood again. To seal that covenant, He placed a rainbow in the sky as a reminder of that promise.
The sin of alcohol soon raised its ugly head as Noah became drunk from drinking wine made from his vineyard. He became unclothed and Ham looked upon his nakedness instead of covering him as Shem and Japheth did. As a result of Ham’s sin, his children were cursed and the descendents of Shem and Japheth were blessed.
The Gentiles descended from the sons of Japheth. Ham’s sons became the fathers of the Canaanites, Philistines and other rebellious nations. The Jewish nation eventually arose from Shem’s descendents.