I've become curious about the history of keyrings / keychains.
Bartok's Duke Bluebeard's Castle is not too specific about period, but
the few images of key bearers I've found seem to be using a cord loop,
as at:
http://en.wikipedia.org/wiki/Image:Barbebleue.jpg

I cant find high resolution Hogarth images, but there seems to be
something similar in the seventh print/painting of The Rake's
Progress.   Would this be knotted, or was there possibly a clasp to
allow keys to be taken off easily?  When do metal rings first appear?
tia- Kekszakalu