[sradman]

I’m guessing that Title Case in English is a logical extension of the European norm of capitalizing proper nouns; a title is the proper noun used to identify a written work.

[rjsw]

This doesn't seem like a European norm to me, maybe it is done in German but I don't see it in English or French publications.

[sradman]

I was making a comparison between European proper nouns (like Jacques and Hans) and English title case. I was speculating why the English title case practice arose.