Japheth, the Eldest
And Noah was six hundred years old when the flood of waters was upon the earth Genesis 7:6
And Noah was five hundred years old; and Noah begot Shem, Ham, and Japheth Genesis 5:32
These are the generations of Shem: Shem was a hundred years old and begot Arphaxad two years after the flood Genesis 11:10
Comparing Genesis 5:32 and Genesis 7:6, Noah’s eldest son would be 100 years old during the Flood. But according to Genesis 11:10, Shem was only 98 years old during the Flood, so Noah’s eldest son must be Japheth, and the difference was by 2 years. This is confirmed by King James Version in Genesis 10:21 Unto Shem also, the father of all the children of Eber, the brother of Japheth the elder, even to him were children born.
Japheth was the elder to Shem by two years, hence Japheth was the firstborn. The name Japheth (H3315 יֶפֶת) comes from the same root word used in Noah’s blessing (Genesis 9:27), where it is translated as “enlarge” (H6601 פָּתָה): “God shall enlarge Japheth . . .”
Outline of Biblical Usage
to be spacious, be open, be wide
(Qal) to be spacious or open or wide
(Hiphil) to make spacious, make open
According to a significant passage in the Targum, Japheth was one who feared God: “And to Shem also was born a son. He is the father of all the sons of the Hebrews, the brother of Japheth, great in the fear of the Lord.”
It says in Genesis 9:1 And God blessed Noah and his sons, and said unto them, “Be fruitful and multiply, and replenish the earth.
It isn’t surprising that in China, the concept of a Heavenly Sovereign, known as Shang Di or Supreme Deity, had been prominently worshipped by the Emperor and its subjects for some two to three thousand years before the advent of paganism brought from over the border in various forms.
Joel Huan
The Mystery of Ephraim 
I like what you have written and concur on Japeth the elder.