Was it former territory? China has seen various power takeovers since the start of British rule in Hong Kong. In 1842, was ruled by the Qing dynasty, in 1912 it became the Republic of China, and in 1949, the Chinese Communist Party took over, leaving Taiwan to the Nationalist government. So you could also argue that Hong Kong should have been returned to Taiwan. Not that that could have happened, but it's not clear cut, IMO.
Interesting argument, but I think at time of the handover Taiwan was not recognized as a state by most major powers (including UK), or do I remember this wrongly?
They ruled China for 37 years. I'm sure they had diplomatic relations
Hong Kong should return to the Taiwanese government. The legitimate government of China
"Before the Nationalist government was ousted from the mainland, the Republic of China had diplomatic relations with 59 countries, such as Australia, Canada, Cuba, Czechoslovakia, Estonia, France, Germany, Guatemala, Honduras, Italy, Japan, Latvia, Lithuania, Norway, Panama, Siam, Soviet Union, Spain, the United Kingdom, the United States, and Vatican City. Most of these relations continued at least until the 1970s, and the Republic of China remained a member of the United Nations until 1971."