King Arthur: The Saxons

Summary pulled directly from Steam - Some text may only be applicable to Steam platform

A long time ago the Saxons came to Britannia as ruthless mercenaries, but they became the devoted warriors of Christianity, united under the rule of King Raedwald.
When Arthur, the son of Uther Pendragon pulled his cursed sword from the stone, the dark age of wizardry and pagan monstrosities returned. These are grave times for Britannia and only the devoted and the faithful can stop this madness.
Call the proud Saxons to Norfolk! Recruit armies and knights and prove that King Raedwald is the real Once and Future King!
King Arthur: The Saxons is a sandbox expansion where you lead the warriors of Christianity, the Saxons against the tides of pagans and the gathering darkness.

Key features:

A brand new campaign with 30+ hours of gameplay where you take the role of the Saxon king. The campaign is set during the events of King Arthur: The Role-playing Wargame, but it follows a stand-alone story with a different ruler.
A totally new gaming experience with the free sandbox gaming mode - the objectives are only strategic goals and not the compulsory elements that lead you through the background story.
A complex diplomatic management: you can establish diplomatic relations with your fellow kings and also with the guild of the outlaws, the Christian Church, the Sidhe, famous knights and brides-to-be.
Customizable Victory Conditions: you can set your own goals for the endgame (the number of Provinces conquered, the number heroes gathered, Gold accumulated and many more)
Customizable characteristics for the gaming environment: you can change the importance of magic in the world or the aggression level of the AI.
5 new unique heroes: gather the knights who follow the traditions of Beowulf, the legendary monster-slaying champion.
3 new and unique unit types: the Guardians have many aspects, but they are all mighty and otherworldly warriors.
New content: 5 new units, 10 new Hero Skills and 5 new Unit Skills; more than 30 unique artifacts (among them 5 sets of items that work more efficiently if collected), more than 30 unique diplomatic and battle quests.
Steam Matchmaking: Allows users to quickly find existing games via server listings, or start new games with a group through a lobby.