Interested in the medieval time period but any other time period is fine.
This isn't the Middle Ages, but since you said that any other time period was fine, there is this answer by /u/NMW about disposal of bodies in World War One, found in the FAQ
As for something in the middle ages, I don't know of exact details, but a great deal of the remains of soldiers killed at the battle of Visby in 1361 were dug up in the early 20th century. The bodies were found in mass graves and many of them, quite unusually, still had a lot of armor on them. Though someone with a background in the middle ages can hopefully tell you more.