purposes during the brief Hồ and Tây Sơn dynasties (1400–1406 and 1778–1802 respectively). A Vietnamese Catholic, Nguyễn Trường Tộ, unsuccessfully petitioned the Court suggesting the adoption of a script for Vietnamese based on Chinese characters. Vietnamese alphabet A romanisation of Vietnamese was codified in the 17th century by the Avignonese Jesuit missionary Alexandre de Rhodes (1591–1660), based on works of earlier Portuguese missionaries, particularly Francisco de Pina, Gaspar do Amaral and Antonio Barbosa. Still, was the dominant script in Vietnamese Catholic literature for more than 200 years. Starting from the late 19th century, the Vietnamese alphabet ( or "national language script") was gradually expanded from its initial usage in Christian writing to become more popular among the general public. The Vietnamese alphabet contains 29 letters, including one digraph (đ) and nine with diacritics, five of which are used to designate tone (i.e. à, á, ả, ã, and ạ) and the other four used for separate letters of the Vietnamese alphabet (ă, â/ê/ô, ơ, ư). This romanised script became predominant over the course of the early 20th century, when education became widespread and a simpler writing system was found to be more expedient for teaching and communication with the general population. The French colonial administration sought to eliminate Chinese writing, Confucianism, and other Chinese influences from Vietnam. French superseded Chinese in administration. Vietnamese written with the alphabet became required for all public documents in 1910 by issue of a decree by the French Résident Supérieur of the protectorate of Tonkin. In turn, Vietnamese reformists and nationalists themselves encouraged and popularized the use of . By the middle of the 20th century, most writing was done in , which became the official script on independence. Nevertheless, was still in use during the French colonial period and as late as World War II was still featured on banknotes, but fell out of official and mainstream use shortly thereafter. The education reform by North Vietnam in 1950 eliminated the use of and . Today, only a few scholars and some extremely elderly people are able to read or use it in Vietnamese calligraphy. Priests of the Jing minority in China (descendants of 16th-century migrants from Vietnam) use songbooks and scriptures written in in their ceremonies. reflects a "Middle Vietnamese" dialect that combines vowels and final consonants most similar to northern dialects with initial consonants most similar to southern dialects. This Middle Vietnamese is presumably