Thanks for the tips. I now fully control the Kingdom. I have revoked all the titles of my prisoners and gave some to my council members and kept half myself. Then I joined a crusade to spain (All of spain is under control of muslim emirates) and now everybody loves me. But my King has this annoying title, 'King Kratislav V the ill ruler' and he has the Kinslayer trait.
So everything was going alright, I had lots of money and was trowing feast and great tourney's around and build lots of improvements in my settlements.
But then my only surviving brother ,who liked me, usurped my crown! I thought, not again! and went to war. However, my brother was allied by marriage to the Byzantium Emperor! So suddenly I had an army of 13000 Byzantines in my Kingdom.
