[Castle]

I've been playing for a few days, and I can't make heads or tails of what I'm supposed to do to keep the population happy. I'm creating most of the "happiness events" described in the manual, but the population seems to just get progressively worse. Most recently, the population complained about my "trade and research treaty", which according to the instructions, is a happiness event. What's the deal? Where can I get some detailed info on how to control this?

Thanks