There are several different translations of Chinese names to the roman alphabet (Romanization or Chinese Phonetic Alphabet). Romanized names are designed to sound similar to the Chinese pronunciation. It allows entering on a standard keyboard and gives a consistent alphabetizing method
Wade-Giles (1912) was developed by Thomas Francis Wade, a British ambassador in China and Chinese scholar who was the first professor of Chinese at Cambridge University. It is based on Mandarin.
Pinyin (1950) was developed in the 1950s by many linguists, including Zhou Youguang
In 1978 mainland China officially adopted Pinyin.
Taiwanese century-old Pe̍h-ōe-jī (POJ) (Church Romanization) was developed by Presbyterian missionaries in Taiwan in the 19th century, is similar to Wade-Giles.
Family Names in this Genealogy:
簡 () is translated to
Jiân/Jean in the Pinyin system and Chien in the Wade-Giles system.
Chinese surname - New World Encyclopedia