My mother's maiden name was Montenegro and I have done some research. The name originates from the Yugoslavian, now Serbian region. Montenegro simply means "Black Mountain". The family resided in Genoa around 1130 but moved to Naples, Italy during the reign of Federico II (1197-1250). Later Montenegros moved to Spain and eventually have spread all over the world. This information was quoted by the Historical Research Center. I am of an Hispanic background.My most current grandparents came from Mexico but I am discovering that the surname Montenegro is not very common in Mexico.Good luck with your research!