On the 30th of August, 870, Þórólfr's daughter Alfrið was born while he was off raiding in Ireland. The emerald isle had become a popular destination for his rowdy warband, with its poorly-defended monasteries and weak local nobility.
Two years later, after five years of profitable plundering, Þórólfr contracted 1800 Lithuanian mercenaries and set his sights to his immediate south, on Chief Hakon of Naumdal. With a host numbering over 2100, Þórólfr crashed upon the territories of Hålogaland and Naumdal, demanding their fealty and naming himself the rightful king. On November 23, 872, Chief Hakon surrendered with winter fast approaching.
In a single war, I've gained the counties of Hålogaland, Naumdal, and Finnmark (the last of which Hakon conquered while I was attacking him). This has quadrupled the size of my realm, and my number of holdings has gone from one to six. Soon enough, I will be able to raise enough men from my own lands that I won't have to rely on foreign mercenaries to anchor my armies.
Before I run out of cash to pay my mercs, I'm immediately declaring a second subjugation war on Tröndelag, to the south of my new holdings. Controlling it would give me the entire Petty Kingdom of Tröndelag, though I still can´t form it as long as I'm Fairhair's vassal.