My first approach was to remain in Poland and work to rebuild it. Like Veldmaarschalk said, it seemed interesting, but everything happened too fast and I basically achieved my goals. Then I noticed that Bajoras was my heir, and after him . . . some Bohemian guy. That gave me the idea, to paraphrase Nikolai, to rise and fall and rise and fall.
I had Bajoras killed just to be sure, and then gave my marshal a lot of land and declared elective law. We recreated Poland, used some cheats to kill off all the Piasts but one line, and then used byzantine to make sure Bolko Piast got Roma but gave up the rest of his land. I also used it to make sure the kingdom stayed in one piece until I could reload, since the coup, restructure and wars guttered my reputation. angryclown hits the nail on the head. This is a more interesting situation that will force me to take the long view on revenge. I will go with Pablo Sanchez's idea to take revenge on those who have wronged the Houst of Piast: the von Frankens, the pope, and Bolko Brochwicz.
Two of you noted two things. Specialist920, I am once again a vassal of the HRE, but this time I'm a one-province count in Italy. And Murmurandus, I do not know if the Bolko wars will come because King Bolko might be overthrown long before I get to him. We'll see.
Thanks for the suggestion on breaking it again, coz1.
Thanks for reading, stnylan and Stroph1 - oh, and Stroph, I fixed the font. Hope it's better.
Oh, and nothing can stop the Knuds, EvilSanta. I have some thirty updates already screencapped and another dozen or so I can do if there's interest after the game gets boring.