I've been getting into medieval history, especially castles and so on, and I'd love an enjoyable book that really wallows in the atmosphere and/or detail.

Could be either historical fiction or fantasy.

I also wouldn't mind any history book recommendations. Anything really good, and I would particularly like to learn more about the very early middle ages, and Continental European history, and the general daily life/economics/history of objects and materials etc.

My preference is middle brow (but not low brow!) reads. Assassin's Apprentice by Robin Hobb kind of fits this description, with an atmospheric castle, if I remember it well enough. However for example The Pillars of the Earth by Ken Follett is a sort of grim book of historical fiction that starts with a child dying violently, and while the depiction of the era is supposed to be well done, that's not the kind of book I want to read.

And if you just get an idea of another book you think I might like even if it doesn't fit in these categories, tell me about it!