Check out this Warband mod!

[Lord_Bernie_of_Voodoo]

The mod is a pretty old one name "Vikingr." Great mod, probably the most realistic one for warband. There's 5 factions, including Rus, Anglo-Saxons, Normans, Irish Celts and of course, Scandinavian Vikings. I don't think i've seen a better looking mod than this one - from the weapons, armor and maps. I'll admit, the community is small, but that's why i'm advertising. A new patch was released and there's now an NA server, so, check it out!!

http://forums.taleworlds.com/index.php/board,202.0.html

[Oberyn]

Last 3 times (like a month appart each) times I've tried logging on to a Vikingr server there were max 2 people there. When I first tried the mod though I ran into some sort of community event so there was a bunch of people and it was awesome. It plays very differently to native or even other mods, quite slow and methodical, teamwork is super important. Worth giving it a try if you can find a server with people on it.

[Tibe]

I played it abit. Its quite the challenge getting to an acctual server filled with acctual people in this mod. Thats the main issue with mods that dont have any presistent world or charprogression or savesystem or something, they die rather quickly.