Peking or Beijing ?
In 1876, Thomas Francis Wade, a British ambassador in China, published the first Chinese textbook in English, in the book, he invented a system to spell Chinese characters, the system was refined in 1912 by Herbert Allen Giles, a British diplomat in China and his son, Lionel Giles, a curator at the British Museum.
This system is called Wade-Giles, sometimes abbreviated as Wade, is a Romanization system for the Mandarin language used in Beijing. The system reached its settled form with Herbert Giles’ Chinese-English dictionary of 1892.
Wade-Giles was the main system of transcription in the English-speaking world for most of the 20th century, used in several standard reference books and in all books about China published before 1979.
It has mostly been replaced by the Pinyin system today, but parts of it, especially the names of individuals and certain cities or trade-marks remain in use today, so that explains why “Peking” comes into “Beijing”, or brand name like “Tsingtao Beer” why not “Qingdao Beer”, or “Chiang Chieh-Shih” for “Jiang Jie-Shi”.
Pinyin or more formally “Hanyu pinyin 汉语拼音”, is the most commonly used Romanization system for Standard Mandarin. Hanyu is the Han (Chinese) language, and pinyin means “phonetics”, the system based upon several preexisting systems, the above mentioned Wade-Giles is one of them, the new Pinyin system was approved and adopted at the Fifth Session of the 1st National People’s Congress on February 11, 1958. It was then introduced to primary schools as a way to teach Standard Mandarin pronunciation and used to improve the literacy rate among adults.
Today the International Organization for Standardization (ISO) adopted pinyin as the standard romanization for modern Chinese in 1982 (ISO 7098:1982, superseded by ISO 7098:1991); the United Nations followed suit in 1986. It has also been accepted by the government of Singapore, the United States’ Library of Congress, the American Library Association, and many other international institutions.
More recently, since January 1, 2009, it is also the official romanization system in Taiwan.
Today it is taught in schools to Chinese schoolchildren and foreign learners the standard pronunciation of Mandarin Chinese, to spell Chinese names in foreign publications and to enter Chinese characters (hanzi 汉字) on computers.
Google Pinyin download: 
Source: Wiki on Wade-Giles System, Pinyin System
