Was Shem or Japeth the oldest son of Noah?

Which of Noah’s sons was the eldest?

In Genesis 9:24 Ham is spoken of as Noah’s younger (or “youngest,” R.V.) son, though some commentators would connect the expression there with his grandson Canaan because of the prominence given to the latter in the curse of verse 25. This leaves us as the two elder ones, Shem and Japheth, and the decision between them depends on the rendering which is accepted as the correct one of Genesis 10: 21. The AN. gives it, “Shem . . . the brother of Japheth the elder,” which would imply that Japheth was oldest; but the R.V. with more probability translates it, “Shem . . . the elder brother of Japheth,” which would
give the honour to Shem.