I knew when my son had to die.


It was Jan. 6, 1151. “The Great,” they called me — King Flann I, unifier of Ireland. A hale and venerable 68 years of age, with nine children my issue, I surveyed my kingdom with pride. From my castle in County Tyrconnell — the same bastion whence my father started our family’s march to power almost a century before — I surveyed the entire emerald isle at my command. I knew my remaining days above this soil were short, precious, and I looked forward to enjoying them in prosperity and peace.


And yet. And yet.


When I returned home from my years of campaigning I realized with horror that all I had wrought had been imperiled by the licentiousness and poor judgment of my oldest son, Prince Mael-Maedoc, Duke of Leinster and scion of the Kingdom of Ireland. In lust, he had sired his own first son not with his wife but with a young unmarried trollop in his own court. Even worse, he had allowed his bastard — who was legally not of our house at all — to become his heir!


With disgust I realized that while I had been conquering new realms I had not paid sufficient attention to the doings under my own roof. My entire realm was at risk of passing outside our dynasty because my own son and successor was a fool.


I knew what had to be done. I called my spymaster, Mayor Constantin of Carrickfergus, to my side. With a heavy heart, I ordered him to assassinate my own beloved son.


But that was not sufficient. Under the law of primogeniture, my bastard grandson was heir to my kingdom. So I had him killed, too. And his brother.


Only then, when I had wiped out my first son’s entire line, could I rest assured that my kingdom would pass to my second son, the brilliant and talented Duke Gilla-Comgain. I was exposed as a kinslayer and reviled, but I went to my death soon after with a clear conscience. I knew that what I had done was for the good of the family.


In other words, it was just another Thursday night playing Crusader Kings II, the captivating new computer strategy game from Paradox Interactive.


If politics, European history, family dynamics and grand strategic ambition interest or entertain you — and if you might like to try your hand as a fictional participant rather than merely a reader or watcher — Crusader Kings II will provide all of the storylines and drama you could ever want.


You start in 1066 as any of hundreds of different counts, dukes or kings from Iceland to Acre. You can jump in as an unknown count on the edge of Hungary, an Italian prince, a duke in the Holy Roman Empire, a Norwegian warlord, the king of Poland, a Byzantine functionary or William the Conqueror himself as he invades England.


You have until 1452 to make your dynasty as powerful as possible. As each individual character dies you take over as his legal successor. If you perish without a legal heir or lose all your territory, it’s game over.


But this is not a game where you are simply moving armies around on a map; that’s the least of it. Its world is populated by thousands of fictional characters, all with their own abilities and personalities. All the courtiers and nobles, all the wives and children and cousins are modeled with their own opinions of and relationships with every other character in the game. The historical, the personal and political are all randomized within parameters that lend eerie verisimilitude to these alternate histories.


For example, when King Flann’s father took over County Tyrconnell in 1066, the forces of Islam controlled a bit more than half of the Iberian peninsula. But over the subsequent decades the kingdoms of Castille, Navarra and Aragon fell to the Moors. Well it turns out that Flann’s uncle had married the widow of the king of Castille (who died fighting the Muslims), so when those kingdoms fell all of the nobles fled to Flann’s court in Ireland, which is pretty much a straight shot north from Spain anyway.