HSBC - a Hong Kong or British bank?

I know it is very complicated and controversial, HSBC the biggest bank in both Hong Kong and the United Kingdom, probably even the biggest in the world. established and incorporated in Hong Kong with British capital during the time of British colonial rule, its headquarter had always been based in Hong Kong until 19 years ago due to the concerns of Chinese takeover. it moved its base to London since then. is it a Hong Kong or UK bank afterall?