I saw an interesting documentary recently about the British Royal art collection, and it included the interesting quote: "At the root of every great fortune is a crime".
The original British Royal art collection was confiscated in 1649 by Cromwell and it's putative owner was put to death! Almost all of it was sold off, with some parts later returned after the restoration and then glorious revolution (which was more or less a coup). The subsequent collection was built up significantly by the Hanoverian's.
I expect that the crime being referred to was the execution of Charles 1st?
In the documentary they were examining a famous piece from the collection depicting Ceasar's conquest of Gaul (France), which, according to the documentary, was effectively a genocide.
A quote attributed to Honoré de Balzac, but when I went to use it a few years ago I wanted a citation and found that his actual words were neither so pithy nor so broadly implicative:
"Le secret des grandes fortunes sans cause apparente est un crime oublié, parce qu’il a été proprement fait."
The secret of great fortunes without apparent cause is a forgotten crime, because it was properly/cleanly done," is my fairly literal translation, but I am not really fluent enough to capture subtleties.
I expect that the crime being referred to was the execution of Charles 1st?