I loved Costain's books on the Plantagenets. I remember that my English History teacher in college didn't like them much because they concentrated so much on the color and feel of the period (in addition to the names, dates, and politics) but that, of course, is what appealed to me. I still think that the small cultural details, even about such seemingly trivial matters as the fashionable cut of a sleeve, speak volumes if you're willing to listen.