Good luck, and have a great week!
I've had this game lying around a while as a friend gifted it to me and it was never my type of game so... here we go!

Description:
The Dark Ages might be drawing to a close, but Europe is still in turmoil. Petty lords vie against beleaguered kings who struggle to assert control over their fragmented realms. The Pope calls for a Crusade to protect the Christians in the Holy Land even as he refuses to relinquish control over the investiture of bishops - and their riches. Now is the time for greatness. Expand your demesne and secure the future of your dynasty. Fill your coffers, appoint vassals, root out traitors and heretics, introduce laws and interact with hundreds of nobles, each with their own agenda.
A good lord will always need friends to support him. But beware, as loyal vassals can quickly turn to bitter rivals, and some might not be as reliable as they seem... Stand ready, and increase your prestige until the world whispers your name in awe. Do you have what it takes to become a Crusader King?
Crusader Kings II explores one of the defining periods in world history in an experience crafted by the masters of Grand Strategy. Medieval Europe is brought to life in this epic game of knights, schemes, and thrones...

Key features:
Start a game at any point between 1066 and 1337 and play until 1453
Pick a Christian lord and make sure his dynasty survives as you play a succession of his descendants through the ages
Gain Prestige for every successive character you play, furthering the glory of your Dynasty
Expand your feudal domain - and keep it from falling apart
Unravel the plots of your courtiers and vassals, each with their own opinions and agendas
Take up the Cross and fight the Moor, the Heathen and the Heretic.
Defend against the onslaught of the Mongol Horde
Struggle with the Pope for control of the bishops
Relive the Middle Ages with up to 32 other players in a competitive multiplayer mode

Requirements:

Windows
OS: XP/Vista/Windows 7
Processor: Intel® Pentium® IV 2.4 GHz or AMD 3500+
Memory: 2 GB RAM
Hard Disk Space: 2 GB
Video Card: NVIDIA® GeForce 8800 or ATI Radeon® X1900, 512mb graphics memory required.
DirectX®: 9.0c
Sound: Direct X-compatible sound card
Additional: 3-button mouse and keyboard

Mac
OS: Mac OS X 10.6.8 or later
Processor: Intel Core Duo Processor (2GHz or better)
Memory: 2 GB RAM
Hard Disk Space: 2 GB
Video Card: ATI Radeon HD 6750 / NVIDIA GeForce 320 / NVIDIA GeForce
9600 or higher, 1024MB graphics memory required

SteamOS+Linux
OS: Ubuntu 12.04 LTS
Processor: IntelR PentiumR IV 2.4 GHz or AMD 3500+
Memory: 2 GB
Hard disk space: 2 Gb
Video Card: ATI Radeon HD 6750 / NVIDIA GeForce 320 / NVIDIA GeForce
9600 or higher, 1024MB graphics memory required.