Alternatively, it need only be about two thousand years old
There are parchments of a similar age, I believe, although yes - they're not exactly books in the fashion of which we are accustomed
Technically, the first "book-shaped books" (by which I mean codices, parchment cut and assembled in rectangular pages, and not volumen, which were rolled parchments) we know are from the 2nd century BC.
There are parchments of a similar age, I believe, although yes - they're not exactly books in the fashion of which we are accustomed