I have scripted a lightweight SV3.3 submod for the British Isles. I'm aware that 4.0 is due sometime soon and i will hopefully be able to update any scripts when its available.
This submod uses the full SV campaign map and will not alter game experience for any other factions
The main purpose of this submod was to represent more historical accuracy in the British Isles during the dark age period. I also wanted to create a more competitive and interesting game when playing the factions England, Denmark and Scotland. The mod will also make these factions more dynamic and is a worthwhile update if you play as any other faction.
No other factions or regions have been modified but the province of Koumbi has been sacrificed to create one of the two new provinces, Galway/Connaught is also gone. The two new provinces are 'Innse Gall' or the island province of Hebrides, Orkney and Mann (settlement is Stornoway) The other province is 'Bernicia' NE England (settlement is Berwick)
Denmark now has Edinburgh and more Norse influence is reflected throughout Ireland and Scotland.
-new characters have been added
-some provinces, settlements and unit names have been changed
-rebel armies have been added
-relations have been modified, Denmark is now at war with Scotland and England
-garrisons have been amended
-win conditions updated
-land bridge between Scotland and Ireland has been removed
-a fort has been added
..and some other small changes.
Please leave some feedback 
* Moved to here: http://www.twcenter.net/forums/showthread.php?t=431721