Forgotten grandson became Khan of Khans.

So i was the Norse catholic pirate King of the Mon island.. I married off one of my daughters to this nomad duke matrilineally and forgot about him..At this point i was in the late game and left the game running in observe mode for about 3 hours... 150 years or so... She gave birth to a son who got the conqueror trait (didnt know we got this in random) and formed the Oghuz empire , became the greatest of khans , got the golden lineage trait ...Now his son has expanded the empire half the size of the map.. has 300k plus troops..400k plus gold... he bacame the dynasty head of my dynasty which has almost a 100 cadet branches... The greatest underdog story ive seen in ck3.