I'm interested in the Arnesian War. Anything you could think of might be helpful.

By knowing the name, you'll have read everything there is about it.

I found this on the UESP, and I don't know how credible it is:

"What started as a simple slave revolt in the House Dres lands of the south built on itself until the swampy plains erupted with blood and fire, pitting Morrowind against Black Marsh. Morrowind's armies ultimately defeated the rebels, but victory came at a price. In the chaos, Symmachus was slain, and Queen Barenziah, rightly fearing for her life, fled across the Empire to the High Rock kingdom of Wayrest. The Queen abdicated her throne, leaving it to her uncle Athyn Llethan, a House Hlaalu noble."

EDIT: I found this at TIL:

"The Arnesian War. Morrowind destroys the armies of Black Marsh. Roris, one of the Dunmeri merchant leaders is captured and slain by the Argonian. This raises the sentiment against the Argonian of Black Marsh. Apparently, this is one of the reasons for the Dunmer to start a war with Black Marsh. Roris himself is venerated by the Dunmeri Temple as the Patron of Furnishers and Caravaners."

Credible, it's a straight rip from thehttp://www.imperial-library.info/pge3/morrowind.shtml

It was not much, but some details were useful. I can use them well.