The Emperor Kao-tsung (1107-1162), whose official name was Kou, and whose familiar name was Te-chi, was the ninth son of the Emperor Hui-tsung. At first he was entitled Prince of K'ang, but on the two emperors Hui-tsung and Ch'in-tsung being taken north as prisoners by the Khitan he established himself as emperor in Hangchou.
Source: wiktionary
The Sung Dynasty is divided into a Northern and Southern Sung, the former when the capital was at Kaifeng, and the latter when Hangchou was the capital.
Source: wiktionary
When the dust settled, there was the Chin dynasty with its own emperor plus two Sung emperors as prisoners in the north, and Kao-tsung, the first emperor of the Southern Sung, in Hangchou.
Source: wiktionary