War of the Roses as a campaign plot. Two noble lines converge somehow, each line thinks it has the rightful claim to the throne. Deciding this long ago was handled by some divine intervention, requiring both houses to come together at some point. They aren't so willing to get together this time. Civil war, or a new king?
A nation was conquered and the conquerers took control and put themselves in all positions of authority. One major problem, the new rulers and the now peasant/ruled class speak entirely different languages.