The de Mariscos were a family that continually got into trouble, on account of continually misbehaving. When William de Marisco was executed at the Tower of London in 1242, it was ostensibly for attempting to have the king murdered, but since he'd also been pirating from the Isle of Lundy, and murdering messengers, he was going to end up being executed at some point anyway. Besides explaining the de Mariscos, we have two rabbit holes! Anne is fascinated by the Isle of Lundy, and Michelle is fascinated by Matthew Paris, and really, there's a lot going on in this episode.