Pretty much what it says on the tin. I've been reading up on political philosophy and the history of political ideology, but as an American, I simply don't have a good grounding in political or party thought and history in Great Britain, which makes it hard to know what being a Tory or Liberal or Whig meant 300 years ago, and so on.
It might be of interest to you to read Bagehot’s The English Constitution, which discusses the government of the United Kingdom and offers a comparison to that of the United States at the time. While the work is, obviously, a bit dated, it’s still an interesting insight.