While I was with in France lately, I picked up an old copy of 'The Emperor' (1978) by Rysard Kapuscinski. It is just wonderful; I can't recommend it highly enough.
It's an account of the last years of the 'byzantine' or 'medieval' court (pick your own picturesque cliche) of Emperor Haile Selassie of Ethiopia, who was absolute ruler of Ethiopia for 44 years. The book uses the voices of courtiers, interviewed by the author, to express the worldview of the court itself, the last imperial court in our time. These people saw themselves standing in an ancient tradition, and they often speak like characters from fantasy or historical romance.
Kapuscinski is a Pole who wrote this under communism, so it's generally seen as a biography of modern totalitarianism, an analysis of tyranny. And naturally there's much in it applicable to our current plight in the 'free' world.
For example, one court insider bemoans that his son has begun to think: "in those days thinking was a painful inconvenience and a troubling deformity. His Exalted Majesty, in his incessant care for the good and comfort of his subjects, never spared any efforts to protect them from this inconvenience and deformity... it truly amazes me that the police never caught the scent, the connection between thinking and mood. They could have easily neutralised these thinkers, who by their snorting and malicious reluctance to show satisfaction brought so many troubles and afflictions on His Venerable Majesty's head." (p.98)
But for me it's the specificity that gives it value, the individual voices of this traditional imperial court.
The whole thing feels quite out of history, and almost reads like fantasy. Which probably explains why I enjoyed it, since I don't usually read non-fiction these days.