The 1300's were a time of great upheval in the East (with the formation of the Polish-Lithuanian super-state) but in the West, around France the social structure was mostly unchanging. Sure, the English Controlled several traditionally French provinces by inheritance and marriage, but no one seemed to care, yet.
But, the Aristocracy of that period where born with the idea that they were intrinsicly better than everyone else. They were spoon fed it as a child. They thrived on it as Teens. They taught it when they were adults.
Many people thought that they were "breeding" people to be great political leaders, great soldiers, and great religious leaders much in the way that they had bred dogs for specific purposes out of wolves. In this case the "Haves" didn't develop to their fullest potential (the vast majority of the time) and the "have-nots" were unable to develop because they weren't born... right... or something.
I can go into weapons and armor of the noble for the day, but reconstructing the home life is far more difficult.