Frederick the Great has been among the historical figures that I have been profoundly uninterested in. I believe one of the core reasons for that has actually been reading Grimberg's Världshistoria (in Finnish translation) at an impressionable age - and that was very pro-Maria Theresa. In mature retrospect she is hardly much more inviting figure. Hard to think of any pre-modern autocratic or semi-autocratic monarch who would have been. In any case Frederick's curious mixture of (mostly) bad art and philosophy and rather Hitlerian gambling in warfare have not seemed very interesting.
Now reading Tim Blanning's excellent biography he emerges as marginally more sympathetic. I have been dimly aware of the main facets of his life, but had not for example realized just how dismally sadistic his father was and how awful his youth in the shadow of that abuse. In that sense even bad art and philosophy seem more fresh than expected. And he can be amusing in his cynicism and disregard of pieties (and the pieties of that disgusting age richly did deserve cynicism and disregard). His surprisingly open homosexuality - or homoeroticism - at least was a kind of a protest too.
But such rigidity and narrowmindedness in the heart of it all. I guess no monarch of that age could have escaped absurd and baseless haughtiness and sheer blindness to any decency and humanity (the whole ghastly era led the priviledged away from such values). And with his awful upbringing Frederick could surely not have escaped the inevitable concequences - thus many of his strengthts became disastrous failings. Speaking of the human being, that is, as a monarch he was not much worse than most.