@Daniel Cheng
Dongjing, Nanjing, xijing, Beijing are all romanizations for the capital cities of the 4 cardinal directions (North, South, East, West)

Dongjing exists as Tokyo, the capital of Japan. Both kanji in Japan and Chinese characters write it as 東京.Tokyo’s old name was Edo, meaning mouth of a river.

In China:
Datong was named “Datong xijing governate” and once one of the five capitals of the Liao Dynasty and the temporary capital of the three dynasties of Liao, Jin and Yuan.
Fengxiang also known as the “Fengxiang governate” of xijing established in the Tang Dynasty
The former name of Chengdu, called xijing by a short-lived successor state to the Ming under the warlord Zhang xianzhong
The former name of xi’an under the Republic of China.
In Korea:
Old name of Pyongyang during the Goryeo dynasty, as its temporary capital city.
Cheongju, was one of the five small capitals of Unified Silla on the Korean peninsula.
In Vietnam:
xijing was a Chinese name for Thanh Hóa, the western capital of Lê dynasty in the 15th century.

東京、南京、西京、北京都是四個方位(北、南、東、西)的首都的漢字拼音。
東京存在于日本,是日本的首都。日本的漢字和中國的漢字都寫作“東京”。東京的舊名是江戶,意思是河口。
在中國:
大同被命名為“大同西京府”,曾經是遼朝五個首都之一,以及遼、金和元三個朝代的臨時首都。
鳳翔,也被稱為唐朝建立的“西京鳳翔府”。
成都的前名,在明末軍閥張獻忠的一個短命國家中被稱為西京。
中華人民共和國時期西安的舊名也叫西京。
在韓國:
在高麗王朝期間,平壤的舊名叫西京,作為其臨時首都。
清州是朝鮮半島上統一新羅的五個小首都之一。
在越南:
西京是15世紀黎朝西部首都清化的中文名稱。