Just today I finished this game. I won't post any spoiler info unless someone specifically asks for it, but I did want to share two things that may be very helpful.
1. Conquering the various cities and towns is completely optional. There may be a way to end the game via that means, but I did not find it. I ultimately took control of all 23 cities and towns in the game, and the only thing I got out of it was money from taxes, and experience points from killing countless guards. I felt it was important to state this because I spent a considerable number of hours assassinating lords and reagents, and if I were to play over again I'd skip it.
2. Someone in an earlier post stated that as they got near the end of the game they found it to be buggy. This is 100% accurate. However, once I was able to ascertain what was happening it was no longer a problem. In other words, the bugs don't impede you in winning at all.
Here's the deal: The final dungeon is designed in such a way that you can actually get OUTSIDE of the dungeon's walls and into the void that is around it. This was evidently done deliberately by the level designer, as there are multiple gaps in the walls. This is the case on more than one level of the dungeon. There are a couple of odd behaviors that result from this ability.
First, there are staircases that you can approach from "the back side". When you go up or down a staircase from the opposite side it was intended to be used, you pop into the next level of the maze also on the opposite side. So it's easy to get disoriented if you do this, and in some cases the auto-mapping feature will cease functioning because you are outside the confines of the dungeon.
Secondly, if you are in the void and you walk too far away from the dungeon, you will literally walk off the map (or grid). When that happens you don't fall
Instead, the game becomes corrupted. The text on the screen becomes garbled, you can't click on the buttons, some buttons disappear, etc. Basically, really weird things start to happen. Eventually the game will lock up completely and you have to re-start DosBox. So avoid this by staying close to the dungeon's walls and not walking off into space.
Now, I believe the reason the level designer put the gaps in the walls was to let you walk around the perimeter of the dungeon. Once you do that on a couple different levels, it will become very obvious where secret rooms are hidden. The final dungeon is massive (much larger than any other in the game) so if you had no other way of knowing where these rooms are, it could take hours and hours of checking for secret doors.
That's pretty much it. Overall, the game is a lot like I remembered it so long ago, and I'm very pleased to complete a journey that I knew one day I would finish. I think it was worth the effort.