I've been watching The Last Kingdom on Netflix lately. I put it on as a distraction one day, but it caught my attention. It's not the most amazing show I've seen in the time period. It looks like another attempt to cash in on the success of shows like Game of Thrones and Vikings, but it is done well. I can't comment on the historical accuracy of the show, but it is almost a master class on how to use NPCs and setting to keep your PCs invested and moving. It's also a good example of how politics in games can work.
The Basic Story
I don't want to give spoilers for the show, but the basic story is this: the main character is Uhtred of Bebbanburg. Early in his life, despite being an English Lord he ends up being raised by Danish raiders. Then, when his Danish family is killed he is framed for it and ends up wanting to reclaim his home/birthright while trapped between the Danes and the English.
Why The Setup Works
The setup works great for a number of reasons. First, there is a large over-arching goal that is tangible, but has to be built up to. Second, there are large forces arrayed all around the main character. Third, those large forces all have reason to dislike the character.
Now there are potential ways and allies also built in, but you have a wonderful situation with a large goal, multiple means to start, and a journey to get there. Oh, and plenty of pointy things to prod if things aren't moving fast enough.
The politics come in with choosing a side. Which side do the PCs choose? Do they remain loyal? Do they play both sides? How do they deal with those who think they're not loyal? How do they handle tests of that loyalty?
Even better though, how do they handle obstacles put on them by allies in an attempt to bind the PCs to the NPCs even more?
The Rest Plays Itself Out
The rest plays itself out with the PCs. Just remember who is in charge of the factions and what they want. Those individual desires - which are clear in the show - can be played to extremes to allow for the continuing of problems that the PCs have to find how to deal with. What do you do when the man controlling the armies you needs keeps wanting to press for peace? What if that person will do nothing without consulting a sorceror of dubious nature and intent?
The show has a collection of interesting names not commonly in use - and thus not appearing often in modern literature or other stories. Characters that are fun to see, and have their own nuances and flaws. It's worth a look. Check it out, just pay attention to how the structure of the tale works.