 The country was effectively divided in two.The West's exposure to Annam and Annamese exposure to Westerners dated back to 166 AD with the arrival of merchants from the Roman Empire, to 1292 with the visit of Marco Polo, and the early 16th century with the arrival of Portuguese in 1516 and other European traders and missionaries.Alexandre de Rhodes, a French Jesuit priest, improved on earlier work by Portuguese missionaries and developed the Vietnamese romanized alphabet Quốc Ngữ in "Dictionarium Annamiticum Lusitanum et Latinum" in 1651.