Prince Pyotr Petrovich Troubetzkoy (1822–1892) was a Russian diplomat, administrator and general.

In Florence he met Ada Winans, an American lyric singer, and with her moved to Ghiffa on Lake Maggiore.

He could then recognize his three sons born from Ada : Pierre (husband of American novelist Amélie Louise Rives), famous sculptore Paolo and Luigi.

Keen on botany, Piotr found in Ghiffa the best place to develop an important botanic garden and build his residential villa.

In 1884, owing to the financial disaster of the Panama Canal construction he was forced to sell the villa in Ghiffa and, separated from Ada, he retired with Marianna Hahn first in Milan where was born their natural son Pietro Troubetzkoy Hahn 1886, and finally to Menton (France) where he died in 1892.