Two weddings and a war
To recap: After Earl Muiredach of Desmond, a county that is mine by rights, refused to become my vassal, I declared him a rebel and raised my feudal levies to take County Desmond by force of arms. My army counts 389 strong, and Muiredach has raised 225 traitors to oppose me.
We're now embroiled in what's called a "de jure" war. What this means is that, since I am Duke of Munster, and County Desomond is "de jure" (by law) part of the Duchy of Munster, I have a rightful claim to it. Crusader Kings II doesn't let me declare war for no reason. I need either a de jure, marital, religious, or fabricated claim to declare war.
To win the war, I need to increase my warscore. It's a value that goes from negative 100 to 100 percent, and the higher it is, the greater the chance my enemy will accept a demand for surrender. If it gets high enough, he might offer surrender himself. My warscore increases every time I win a battle or capture a castle, and goes up over time for whichever side occupies the disputed territory.
Brian macMurchad, heir to the Duchy of Munster, and Princess Sigrid of Denmark, second eldest daughter of King Svend II, are married. The day after, Brian's father, Duke Murchad I, is married to Alfhild of Rogaland, daughter of a Norwegian count. Great celebrations are held across Munster, with Irishmen from the grooms' lands and Norsemen from the bride's sharing drinks, tales, and more than a few brawls.
Success! My house is now married into a noble line from Norway, and the ruling Danish royal house of Ylving. Since King Svend has one daughter and three sons who are older than my heir's new bride, it's still unlikely that an ua Brian will ever inherit the Kingdom of Denmark. But as a consolation, I can now call on the mighty Danes in times of war. They aren't guaranteed to answer, but protecting his daughter will cause King Svend to consider such a request very seriously.
The flipside is that I've given ammunition to Irish loyalists who were already wary of me allowing a Norseman (Lord Mayor Ragnvald of Ormond) to hold my most important vassalage. From this day forward, House ua Brian's heirs apparent will all be either married to or descended from Norse nobility.
My son's new bride, Princess Sigrid, is an 18-year-old charismatic negotiator, humble and diligent, but also said to be cruel and short-tempered.
My (second) wife Alfhild, the new Duchess of Munster, is an underhanded rogue, though also just, temperate, patient, and kind in spite of it all. She also has a harelip, which wasn't in the brochure.
With marriage checked off, it's time for me to pick a new Ambition. Of those available, "Have a Daughter" seems like the best choice. With any luck, my 36-year-old wife will conceive.
October 3, 1066:
Desmondian forces led by the pretender Earl Muiredach besiege Waterford, Ormond. Knowing the defenders there are capable of holding out for many weeks, Duke Murchad marches his armies from the wedding pavilions, around the Desmondians, and toward the traitor Earl's holdings.