The answer is "wanting to disguise the truth they have uncovered."
Some historians find this tough. One of the reasons would be because not all people may or may not, like the truth. Some historians would omit some part of the truth to keep violent reactions from the readers or outsiders.
A mark or character used as a conventional representation of an object, function, or process, e.g. the letter or letters standing for a chemical element or a character in musical notation.
