I started a new game as
Hvitserk of Jorvik. At some point I'm fighting the king of Wessex for control of London. Sometimes in CK2 you just need some time to browse family trees, so I discover my advisary and his wife have the great pox. How convenient. I decide to figure out if this pox has spread, so I check the court of his ally, the king of Mercia. Now, while my army was on the way to London it had sacked Tamsworth, seat of the king of Mercia. While I discover that the king of Mercia doesn't have the great pox but is merely stressed, I also discover that apparently I hold his wife, the queen of Mercia, captive in my prison. Quelle suprise! And to top that off, I'm also holding his three daughters.
A sane man would've ransomed them, but I'm a viking. Concubines, concubines everywhere!