Where the Nguyen name comes from

Nguyen is the most common surname in Vietnam, carried by somewhere between 30 and 39 percent of Vietnamese people. It is written 阮 in chu Han, a character that originally wrote the name of a state in Gansu and also named the ruan, an ancient Chinese instrument. The same character is romanised as Ruan in Mandarin and Yuen in Cantonese, so three surnames that look nothing alike are one word underneath. Outside Vietnam the diacritics usually fall away, and Nguyen is what is left.