Blood and Steel, build 1.251.

Official Forum, please visit it and support the mod

Non-Spoiler Short Description (as of 1.251):

Battle the skeleton hordes and the Dark Armies!
Cool class system that makes the entire game different.
Beautiful new scenery and a more immersive experience.
Awesome skills make your whole party stronger as you grow and learn how to play.
Regional Mercenaries add color and spice to the game.
Useful options to alter and deepen the gameplay.
Advanced tactical AI.
Cooler random battle scenes.
New and reworked sieges for every castle and town.
Better-looking landscapes and terrain.
Hundreds of new items.
Completely rebalanced faction armies.
Dozens of major gameplay changes.
New game balance.
New ways to make money, and a new economy.
You can ride camels into war.

Generally, it's like a whole new Warband.

Full description of the many, many features is here.

Various cool gameplay videos!

Frequently Asked Questions, please read them before posting

If you've downloaded a previous version, and want to know what's in the current build, changelogs can be seen here.