Why is the UK Population Spread out like that?

-Wales and Scotland have lots of Mountainous Areas, making it Hard to Develop and Utilise -Liverpool and Portsmouth has had the Perk of Natural Harbours and Ports, meaning more Trade -Newcastle and Cardiff exploited the Natural Resources and also the Natural Formations, like Rivers -Majority of UK Cites are on Flatlands - Easier to Develop -London is the the Hub of England, being one of the Biggest Financial Centres in the World