At long last, I can proudly say that I have finished Piers the Plowman! I would rather read this than the Romance of the Rose any day, but it was in fact rather long and on the repetitive side.
This is a long alliterative (but unrhymed) poem in Middle English, written about 1360 or later. I read it in a modern English translation--a very old Penguin copy. (Those old Penguin paperbacks must have been very well-made; the spine is still perfectly sound and flexible though it dates from about 1960 or so.) The whole thing is a huge allegory in the form of a series of visions about life, faith, and how we should live. There is a lot of social criticism, and even more theology, much of which is a little weird by medieval Catholic standards.
I was glad that I had read A Distant Mirror before tackling this text, because Tuchman mentions Langland several times and explains much of the background. Piers the Plowman was written partly in reaction to the ravages of the Black Death and to the society that was so hard hit by it.
The poet spends much of the text trying to find out how to live properly by searching for Do-well, Do-better, and Do-best, who will be able to tell him what to do. He meets endless allegorical characters who give him their perspective, and later on he meets Abraham (complete with patriarchs living happily in his bosom), sees the life of Jesus along with His crucifixion and the harrowing of Hell, and finally sees the Anti-Christ. So there is sort of a religious history of the world included, though it has so many speeches and allegorical figures that it's hard to tell what's going on.