Vanity Shelfmark

The pope's personal vehicle has the number plate SCV 1 (the letters stand for Status Civitatis Vaticanae). It's one of the world's grandest vanity plates. By analogy, the "first" book in the Vatican Library, Vat.lat.1, ought to be a very special book. It belongs to the Vatican's own collection (not the ones which the pope purchased or captured in war or otherwise took over). It's in the Vatican's own  language (not Greek or Hebrew). And the Vat.lat series is for manuscript codices, not printed books.

Vat.lat.1 arrived online in digital form on October 2. Red leather binding, somewhat scuffed, and on the spine just about the poshest of all labels a library book could ever carry. These labels were printed postage-stamp style and torn off a sheet, so this label may even carry a bit of nineteenth-century DNA in the form of a holy lick on its back:

 

It's a Vulgate Bible, gloriously illuminated in some year between 1426 and 1475. Reader @TuomasLevanen points out this fine initial in Chronicles folio) showing teacher and student:

It would be nice to suppose this was the first book purchased from a bookseller when Pope Nicholas V set up a public library at the Vatican in 1451.

But that is not so. The early papal librarians sought order in the chaos by shelving like with like, and then attaching numbers serially to the codices, since they lacked anything sensible like the Dewey Decimal System which I assiduously learned in my youth. The bibles came first, so many of the books in the range 1-100 are study bibles.

This was not the personal bible used by popes, as far as I know. Nor is it the authoritative text of the bible, like the one-metre bar kept in Paris as the source of all measurement on the planet. The approved text of Jerome of Stridon's Latin, the Nova Vulgata (online), is a composite compiled from many far older manuscripts than this one.

But if you ever get elected pope and decide to read all the books in your library starting from number one, this is the volume to begin with. You'll need to be patient. As far as I know, there are more than 15,000 codices in the Vat.lat series alone.