Analysis of information sources in references of the Wikipedia article "Nguyen" in English language version.
According to a study by the Faculty of Literature, VNU HCMC, changing surnames to 'Nguyễn' was quite common among the descendants of the dethroned dynasties. The main purpose was to change the identity and avoid revenge on the ruling family before or after. Typically, when the Hồ Dynasty collapsed in 1407, the descendants were afraid of revenge by the Trần descendants (because Hồ Quý Ly had overturned the Trần dynasty before), so they changed their surnames to Nguyễn.
The combination of consonants ng often comes at the beginning of a word, as in the surname Nguyễn, and it is one of the other difficulties (fortunately there are not many) that Vietnamese consonants pose.
