Originally uploaded by _gee_
Fraser Nelson, a conservative journalist whose father was born in Glasgow East, has written a couple of good background pieces about that place (which is, of course, where a by-election will soon take place).
This article from The Spectator is a good introduction from a political perspective.
For a wider and more historical view, read this one.
I highly recommend reading both. People from outwith Scotland might be somewhat shocked by some of it…