Hi -- this came up on a Latin group that I'm part of on Facebook. Does anyone know when people first started routinely marking first-declension ablative singular endings with long-vowel marks? I wrote that it was a medieval innovation developed as a sort of "crutch" for people whose first language was not Latin (i.e. everyone) -- which is true as far as I know, but I'd like to be sure that what I wrote is correct -- and anyway, "medieval" spans a vast length of time, and I'm curious when exactly they first appear.