So, they're French. They're printed on paper, not card. I don't know the manufacturer, but French cards of this era are pretty good for dating because the Jack of Clubs holds the tax stamp. This one says: "ADMINIST. DES CONTRIB. INDIR. 1816" (meaning "administration of indirect taxes 1816"). The 1816 tax stamp was replaced in 1827, so I know that my pack dates to the 10-year period 1816 to 1826. They're therefore around 200 years old.
It's amazing they've lasted this long, given that they're just paper. My guess is that they've done so by not actually having been played with except maybe for games of patience.