Then he pointed. "These are the seven Great Houses right now," he explained. This was the sort of thing that had been impressed upon him as a child, frequently enough and with enough force that unlike most of the things his grandmother had tried to teach him, much of it had sunk in. "Most of the Blacks are either dead or in Azkaban, and their Head of House is pretty old. Susan Bones - she's in our Herbology class - is the only Bones left except for her great-aunt who isn't married, so even if Susan has kids the name'll change. There's a Lord Greengrass right now but he's only got daughters, so their name is probably changing soon or outright disappearing, especially since a lot of the time daughters of Great Houses marry people from other Great Houses - like I'd bet you a lot of money at least one of them marries Malfoy - and if they both do that, you still end up one House short if Lord Greengrass dies without having a son." And then there was something complicated about Wizengamot votes which frankly Neville did not understand at all and would not try to explain, but which had some interaction with the way Lord Malfoy had way more political power than anyone should ever be allowed to have. He continued, "I'm the only Longbottom except for my great-uncle, my Gran married into the family. And great-uncle Algie hasn't got kids, so - "