Anyone know what the *last* conlangs conference was?

I'd like the info for a press release I'm writing up.

I vaguely remember reading about some conference(s?) in Europe
somewhere around a century ago, about planned languages and etc - but
I forget where I read it, and where and when they were (and what was
their actual exact topic).

Does anyone know and/or can you furnish a reference?

Thanks,
 - Sai