北京點解有2個英文名ge?

簡單講，Peking是古代中西交流時，西方人給“北京”的音譯，是個傳統。
而在共產黨統一漢語拼音方案後，按照這個新方案“北京”應該叫Beijing，便在國際間推行為正式名稱。

中文裏類似的問題有很多。如果你是外國人，你還會問為何Sun Yat-sen又叫Sun Zhongshan, Sun Wen etc...香港人的身份證名稱也其實很麻煩，中文姓名英文姓名等等又不統一。“臺灣”又可寫作“台灣”，又名福爾摩沙Formosa……呵呵。

BEIJING 係國語拼音

PEKING 係英語拼音

北京(Beijing的舊譯)
Names
Beijing or Peking (北京) means "northern capital", in line with the common East Asian tradition whereby capital cities are explicitly named as such. Other cities that are similarly named include Nanjing (南京), China, meaning "southern capital"; Tokyo (東京), Japan, and Đng Kinh (Chinese: 東京, now Hanoi), Vietnam, both meaning "eastern capital"; as well as Kyoto (京都), Japan, and Gyeongseong (京城; now Seoul), Korea, both meaning simply "capital".
Peking is the name of the city according to Chinese Postal Map Romanization, and the traditional customary name for Beijing in English (passports issued by the British Embassy are still printed as being issued by the "British Embassy, Peking"). The term Peking originated with French missionaries four hundred years ago and corresponds to an older pronunciation predating a subsequent sound change in Mandarin from [kʲ] to [tɕ][15] ([tɕ] is represented in pinyin as j, as in Beijing). It is still used in many languages.
The pronunciation "Peking" is also closer to the Fujianese dialect of Amoy or Min Nan spoken in the city of Xiamen, a port where European traders first landed in the 16th century, while "Beijing" more closely approximates the Mandarin dialect's pronunciation.[16]
The city has been renamed several times. During the Jin Dynasty, the city was known as Zhongdu (中都) , and then later under the Mongol Yuan Dynasty as Dadu (大都) in Chinese[17] and Daidu to Mongols[18] (also recorded as Cambuluc[8] by Marco Polo). Twice in the city's history, the name was changed from Beijing (Peking) to Beiping (Peiping) (北平 Pinyin: Beiping; Wade-Giles: Pei-p'ing), literally "Northern Peace". This occurred first under the Hongwu Emperor of the Ming Dynasty, and again in 1928 with the Kuomintang (KMT) government of the Republic of China.[8]