Hello, lore buffs, I've searched and searched, but I cannot find what year Nova Orsinium was destroyed. All I know is that it was in the Fourth Era.
I'm writing a fan-fic and need the date. Thanks in advance!

I dont think a date is known.
As far as Im aware it is mentioned somewhere in passing by a single line, or maybe two.

I think a safe bet would be to place it somewhere between the events of the Infernal City and Skyrim.

Thanks! I'll try and figure out a date here in a bit. You might like to check out what I've got so far. ;D http://www.gamesas.com/topic/1384514-the-many-writings-of-dromok-gro-brosh/page__pid__20995821#entry20995821

Thanks for the link, interesting story.

Actually, the books made it clear Orsinium was destroyed before the books, The Infernal City and Lord of Souls. The orc soldier in the 2nd book was around when she fled its destruction. If anything, it happened somewhere after Oblivion and Infernal City.