I started a serious game. 867, the Petty King of Uppland (which I renamed Niflheim). So I began, forged alliances, fought a few wars, and died.
My heir, Finwe, named for the first High King of the Noldor (High Elves) in Tolkien's book The Silmarillion.
He wasn't the greatest, some of his Lords rebelled, and his realm shrunk down to his demesne and about 5 other counties. Again, I forged several alliances. The first major attempt on my realm was from the realm of Ostergotland (Swedish is a bit messed up with the g=y, so it's pronounced a little like Austeryauteland). They got their asses kicked. Right after, Denmark invaded with around 4000 troops. I was about ready to surrender because my only allies with any reasonable troops were in Jorvik (York, England) and they still only had like 750 to add to my ~1900. Thanks to having great Knights, I somehow crushed the entire Danish army in one long battle where they sent half their troops at me, and then the other half hit after Niflheim’s forces defeated the first half. The Knights seemed to make a big difference in the battle’s, lots of "Svein tore of Hrothgar's head" type stuff =D
For a while, it was calm, I focused on building up my three counties.
When Finwe was in his 40s, he expanded a little, and seized Gotland and Ostergotland County, the capital of the first guys who invaded me - they had broken up a bit thanks to the inheritance laws. Finwe then expanded his demesne to 4 counties. And began raiding + building them up.
When he was in his 50s, Finwe looked to the future. His realm had grown to 13 counties, thanks to conquests from his vassals. He had three sons with his Genius wife - Feanor, Fingolfin, and Finarfin. Feanor and Fingolfin were inferior in traits to Finarfin, so spending some precious Renown and Prestige, Finwe disinherited them,. His entire realm would go to Finarfin - who was way younger than the other two. Finwe had made sure people of his dynasty had married into the families of Counts ranking below them... he then orchestrated the murders of several, making those of his House and dynasty the probable heirs to those lands. But he was now a known murderer (since he got caught on a few occasions).
In his late 50s, with two sons out of the inheritance line, Finwe gave Feanor and Fingolfin, and their young families some land. So he seized a county from a vassal. Being unpopular, this triggered a massive civil war against the Tyrant, with most of the realm of Niflheim rebelling. Niflheim crushed them, imprisoned the leaders, and had their counties revoked and given to Finwe's kin. Around this time, Finwe crowned himself King (instead of Petty King, which is the same as a Duke) of Niflheim. Finwe then expanded his realm by a few counties, nothing major.
Finwe noticed Denmark had expanded. He beat them once, and so invaded their realm to vassalize the entire Kingdom. He conquered Denmark, and then also declared himself King of Sweden, making Finwe King of Sweden, Niflheim, and Denmark. It looked like a small Empire of about 40 counties (foreshadowing for a later post, I'm not there yet).
And to end the story, Finwe isn't dead yet. He's into his sixties now and still conquering pieces of Norway and accepting the fealty of anyone who will bend the knee.
I'm more or less waiting for Finwe to die at this point so I can play my Genius character, Finarfin. My goal for Finarfin is to crown himself Emperor of the North. But it's the title that's of concern, not the lands and responsibilities that come with it. The expansion to get there is incidental, and I'll likely do what I can to shed off a few pounds. A small and powerful realm focused on raiding and becoming rich, marrying off members of my house to foreign realms and helping them rise to the top. Although, if my vassals build an Empire for me, I won't complain, more tax dollars later.
I haven't figured out how to duel yet? Ah well, it was kind of a repetitive action which killed more than a few good characters in my games of CK2, just to gain stats and bloodlines.