Seeking medieval stories... from medieval writers - not modern fiction.
I currently have a personal project where I'm writing tabletop RPG adventures (for Ars Magica, Mythras, DnD) based on the stories told by medieval writers. If we have a medieval game world, then why not use medieval stories! So, it's a process of taking stories, and making them work for a modern audience while trying to retain their essential medieval character.
Problem: I don't know what I don't know. The works that I'm basing the adventures on are very... English! Generally British-based writers, whose works are available in English, which get studied at British universities... because that's what I know. So I've got Gervase of Tilbury, Gerald of Wales, William of Malmesbury (beause the Witch of Berkeley is a must!), the Burton Abbey revenant story... you see the pattern? Very British! Sure I'm working with a few texts from further afield - Burchard of Worms (eating human hearts and then doing what?!), Giovanni Boccaccio, the Cóir Anmann... but very few, compared with the British sources. So what don't I know?
Thus, I am seeking the widsom of Reddit! Can anyone recommend (available in English, or in a text format that I can legally machine-translate) other medieval European writers or stories that I should be looking at? Every country in Europe must have stories that are as cool and RPG-worthy as The Witch of Berkley or Walter Map's crazy stories. But I don't know them... yet!
Any recommendations?