I think there are broader, more subtler issues though, like it’s not that the historian votes Tory and therefore always bigs up old Tories, it’s a way of looking at the world. School history was always very “whiggish”, the great man theory of history, and that’s why you learn about kings and people, these singular figures who supposedly bend history to their will. But other historians come at it from a totally different angle - like Marx for example - and say that history is actually shaped by a totally different factor (the class relationship and modes of production in his case).
I’m not a historian though, would love to hear from someone who did a degree and is more up on these ideas than I am