conventionally dated from the end of the Franco-Prussian War in 1871 to the outbreak of World War I in 1914; characterized by optimism, regional peace, economic prosperity, apex of colonial empires and technological, scientific and cultural innovations
The total income hierarchy is then dominated by very high incomes from capital, especially inherited capital. This is the pattern we see in Ancien Régime France and in Europe during the Belle Époque,
on a "hyperpatrimonial society" (or "society of rentiers")
You would have to go back to the Belle Époque (1900-1910) to find French wealth holders so prosperous