What is a "faction"? - Tudor EnglandWatch
To my understanding a 'faction' is a group of courtiers with a shared interest that work together to push that interest. For example, during Henry VIII's 'Great Matter' - when he was employing various strategies to divorce Catherine of Aragon - the Aragonese faction formed in the Chamber in her defence against the anti-Catholic implications of the divorce. I'm not sure if the term is strictly tied to court though, might be something to look into
In the context of Tudor England, most significantly probably are the Conservative (Catholic) faction and the Reformist (Protestant) faction. I hope I've explained it somewhat!