[thejeff]

It's certainly nowhere near that deterministic. I've just looked at saved games where events have occurred outside of my 10 lowest numbered provinces.
In fact, just from that quick look, I don't see any obvious pattern. Events seem scattered throughout my empires. In the first game I checked one occurred in my highest numbered province. (Small map, but still...)

Furthermore, when event messages are given they don't appear in province order. Since every thing else in the message list is shown in the order it happens (Ritual casting, battles etc) that's at least an indication that events aren't generated in province order.

Squirrelloid, have you actually tested this? And how? I don't see a way to do it other than brute force: Huge empire, lots of turns and do some serious crunching of the results if they aren't obvious.