I'd surmise that over 591 years (short of an exhaustive study) many 'rich' families have -not- remained rich. I'm not sure what 'rich' means; who's in a positio

I'd surmise that over 591 years (short of an exhaustive study) many 'rich' families have -not- remained rich. I'm not sure what 'rich' means; who's in a position (or even can be) to know who was objectively 'richest' then; and centuries have a tendency to erase many or most fine details, and to embroider others.