In a press release:

"Paradox Interactive, a publisher of games and a proponent of all religions, and Paradox Development Studio, today announced a new expansion to the world of Crusader Kings II, the critically acclaimed RPG strategy title. The forthcoming expansion, titled Crusader Kings II: The Old Gods, will add a number of widely requested features to the game, including the ability to play as a Pagan or Zoroastrian ruler, expanding empires through war, pillaging, and ruthless brutality. Players will also be able to begin their in-game reign as far back as the year 867 AD, making The Old Gods officially the Paradox title that spans the longest period in history.

In the year 867 the Old Gods were still mighty. In England, the Raven Banner flew as the Great Heathen Army pillaged its way across the land, deposing kings and establishing the Danelaw. In the East, Rurik founded the state of Russia, and in the forests and steppes of central Europe, pagan tribes were on the move...

Crusader Kings II: The Old Gods lets players step into the boots of a pagan chieftain, approaching the brutal backstabbing world of Crusader Kings through invasion, adventure, and holy war.

Features:

Religious Turmoil: Restore the Old Gods to prominence through sacrifice and divination, or force the pagans to convert through new missionary missions

Earlier start: 200 years of more gameplay with the special 867 AD bookmark

Rebels With a Cause: Rebels are no longer faceless rabble, but led by defined characters with specific agendas

Adventurers: Watch as landless younger sons and charismatic warriors raise armies

Pillage and Prosper: Loot provinces and burn cities to the ground - lest your warlike people grow angry during extended peacetime!

Heathens: Convert them or play as them and survive, reforming your faith to stand the test of time

Prepared Invasions: Declare your intent to invade a rich target, and watch adventurers and opportunists flock to your banner.

Unholy UI: A new pagan interface is available alongside all-new events, decisions, and units

Crusader Kings II: The Old Gods is scheduled to release in Q2 2013."