How it began
The alphabet was developed in the early 17th century by the Portuguese Jesuit missionary Francisco de Pina and other Jesuits working in Vietnam. A study indexed on Academia.edu states that Pina had a Latin-based transcription that marked Vietnamese tones by 1622. The work was continued by Alexandre de Rhodes, who compiled a Vietnamese, Portuguese and Latin dictionary printed in Rome in 1651. The script was made by foreign missionaries, but it was made in Vietnam, for the Vietnamese language.
Before it existed
Before the alphabet, writing in Vietnam used Literary Chinese for formal purposes. Vietnamese itself was written in Chu Nom, a script that represented native words with borrowed and modified Chinese characters. Both required long study of characters.
How it works
The alphabet has 29 letters. Seven of them carry diacritics that create extra vowels and one extra consonant: a with breve, a, e and o with circumflex, o and u with horn, and d with a stroke. Five further marks placed on vowels show the tone of each syllable.
How it spread
The name chu Quoc ngu appeared in publications such as Truong Vinh Ky's grammars and the newspaper Gia Dinh Bao by 1867. In 1906 Emperor Thanh Thai issued a decree allowing parents to choose a curriculum in the script, and the Tonkin Free School promoted it in 1907 and 1908. The French colonial administration enforced it in 1910 and suppressed the Confucian examination system in 1917, while primary schools taught Vietnamese in the new letters.
Where it stands today
Chu Quoc ngu is the standard writing system of the Vietnamese language. It replaced Chu Nom as the preferred way to record Vietnamese literature from the 1920s. It is fully supported by Unicode on digital platforms and operating systems, including the letters with diacritics and the five tone marks.
