The “Black Nobility” are/were the oligarchic families of Venice and Genoa, Italy, who in the 12th century held the privileged trading rights (monopolies). The first of three crusades, from 1063 to 1123, established the power of the Venetian Black Nobility and solidified the power of the wealthy ruling class.
The Black Nobility aristocracy achieved complete control over Venice in 1171, when the appointment of the Doge was transferred to what was known as the Great Council, which consisted of members of the commercial aristocracy (among them the infamous de’Medici family). Venice has remained in their hands ever since, but the power and influence of the Venetian Black Nobility extends far beyond its borders, and today it is felt in every corner of the globe.
https://prepareforchange.net/2018/02/27/who-are-the-black-nobility/
The black nobility or black aristocracy (Italian: nobiltà nera, aristocrazia nera) are Roman aristocratic families who sided with the Papacy under Pope Pius IX after the Savoy family-led army of the Kingdom of Italy entered Rome on 20 September 1870, overthrew the Pope and the Papal States, and took over the Quirinal Palace, and any nobles subsequently ennobled by the Pope prior to the 1929 Lateran Treaty.[1][2]
For the next 59 years, the Pope confined himself to Vatican City and claimed to be a prisoner in the Vatican to avoid the appearance of accepting the authority of the new Italian government and state.[2]
https://en.m.wikipedia.org/wiki/Black_nobility
The most powerful of the Black Nobility families are located in Italy, Germany, Switzerland, Britain, Holland and Greece in that order.
https://www.bibliotecapleyades.net/sociopolitica/esp_sociopol_blacknobil01.htm
Among such Romans are the “black nobility,” families with papal titles who form a society within high society, shunning publicity and not given to great intimacy with the “white nobility,” whose titles were conferred by mere temporal rulers
https://www.britannica.com/place/Rome/People#ref387588
