Why is Ἰάκωβος James and not Jacob?

One of my students asked this rather fundamental question last week. Good question, and I hadn’t thought about it before, and I need your help to answer it.

BDAG says that the name Ἰακώβ (יַעֲקֹב) is “the un-Grecized form of the OT, is reserved for formal writing, and esp. for the patriarch. It is also spelled Ἰακούβ.

The Greek lexical form Ἰάκωβος, with an alternate spelling Ἰάκουβος, is the Hellenized form of Ἰακώβ. 

The normal English translation is “Jacob”; “James” does not appear in the OT (of the ESV). “Jacob” occurs in the NT 26x, always of the patriarch except for the two references to Jesus’ paternal grandfather (Matt 1:15f.).

Unfortunately, I do not have access to the resources that answer this question definitively. BDAG says to check the Oxford English Dictionary; if anyone has access to this and can post their discussion, that would be great. I am hesitant to continue without resources, but here is the best I can see.

From what I can tell, the shift from “Jacob” to “James” is more related to changes in spelling through a series of languages:

• Latin: “Iacobus” (or “Jacobus”)
• Late Latin: “Iacomus” (the b and the m sounded similarly)
• My copy of the Vugate has: “Iacob”
• Middle English: Jacomus

One source I read says the French “Gemmes” is what became “James.” My old Websters Dictionary (I still like paper dictionaries) says that “James” is from the French, which in turn was derived from the Late Latin “Jacobus.”

Wikipedia says, “The development Iacobus > Iacomus is likely a result of nasalization of the o and assimilation to the following b (i.e., intermediate *Iacombus) followed by simplification of the cluster mb through loss of the b.” This seems to hold up from other sources I am reading.

By the time you get to the King James, the name “James” was firmly established (for whatever reason), and they used that instead of “Jacob.”

So I hesitate to publish a blog without a clear answer, but I am curious and invite you to help me solve this riddle.

I have been getting lots of feedback on this one. Interesting. One story that was often repeated was how King James wanted his name in the Bible and so told the translators to change it. I had never heard that, and it is not correct.

The consensus is that the name goes from Hebrew to Greek to Latin to French and finally to English, and it is the succession of changes that account for the changes. One person wrote: Yaʻaqov (Hebrew) → Iacobus (Greek) → Iacomus (Latin) → Jammes (Old French) → James (English).

Someone else posted the OED entry: "Old French James (Gemmes, *Jaimes) = Spanish Jaime, Provençal, Catalan Jaume, Jacme. Italian Giacomo < popular Latin *ˈJacomus, for ˈJacobus, altered from Latin Iaˈcōbus, < Greek Ἰάκωβος, < Hebrew yaʿăqōb Jacob, a frequent Jewish name at all times, and thus the name of two of Christ's disciples (St. James the Greater and St. James the Less); whence a frequent Christian name."