This is Castle Auron.
A mod created out of boredom.

What is this mod?
This mod adds a completely new castle called Castle Auron with it's own armours, voiced npcs and a quest. Due to the way the people of Castle Auron work (they basically help out Cyrodill with it's battles) they do appear in some of the main quest's big fights. Once you complete the quest, you also gain a follower to help you on your adventures.

Installation
Just drag everything in the file to your Oblivion/Data folder and it should be good to go!

Known bugs
The steam version of Oblivion tends to glitch out as the meshes look for the textures in the normal Program Files Oblivion Folder. 
I've uploaded a steam version of the mod which reroutes the texture path to the default steamapps folder so this should fix that for most of you however if it doesn't you can use PyFFI to get it to automatically change the texture path (from my understanding)

Some credit
JackoOs Knightly Armoury is where I got the helmet from, thanks guys.