re: Oldest book you own?

I have a 2nd edition collection of the 1776-1781 first 3 volumes of Edward Gibbon's Rise and Fall of the Roman Empire; the edition thing is a little dicey, as it was the first multivolume set, and Gibbon had a nasty habit of revising his work as he went and new 'complete editions' were printed, throwing off the numbering.

It still has the original maps, but the binding is falling apart. I really need to get them to a professional for restoration.